PureAire 99118 Air Check O2 Water Resistant O2 Monitor Instruction Manual
- June 4, 2024
- PureAire
Table of Contents
99118 Air Check O2 Water Resistant O2 Monitor
Air CheckO2
Water Resistant O2 Monitor
Instruction Manual
Part number 99118
PureAire Monitoring Systems, Inc. 1140 Ensell Road
Lake Zurich, Illinois 60047 Phone:
847-726-6000 Fax:
847-726-6051
Toll-Free: 888-788-8050
pureairemonitoring.com
Rev. 4.11 October 2022
Welcome to PureAire Monitoring Systems
I’d like to thank you for investing in our continuous life safety and process
control toxic gas monitoring systems.
PureAire offers an unbeatable combination of experience and innovation in
solving the safety and environmental needs of our customers. We are capable of
providing small systems of a few points to a total multi-point turnkey
computerized package.
PureAire’s proprietary sensor cell technology and state-of-the-art electronics
are designed to interface with the latest distributive or PLC based control
systems. We believe that our experience, innovative products, and commitment
to service will satisfy your specific monitoring needs now and in the future.
Our growth is a result of our total commitment to supporting our customers. We
are available 24 hours a day, 7 days a week to help you when you need us. Our
24-hour Emergency phone number is
1-847-420-3814. We can provide field
service, preventative maintenance programs and training to your technicians in
the operation of our equipment. Our goal is to provide the best after sale
service and support in the industry. That is just one way PureAire takes that
extra step to ensure your complete satisfaction.
Thank you again for investing in PureAire Monitoring Systems for your
monitoring needs and I’m proud to welcome you to our family of valued and
satisfied customers.
Sincerely,
Albert A. Carrino President
Please Read Before Installation
The following will damage the Air Check Oxygen monitor.
1. The Air Check O2 monitor requires 24 VDC regulated power. Please Do Not
connect the monitor to any voltage that exceeds 24 Volts DC, or ANY AC
Voltage.
2. Do not power the Air Check Oxygen monitor with the oxygen sensor unplugged
from the main PC board. Do Not Connect the O2 sensor to the PC board while the
monitor is powered. This Will Damage the O2 sensor.
3. The oxygen sensor cell is matched to the electronics. Never exchange the
electronics with an oxygen sensor from a different monitor.
4. When testing Sample Draw and Ex type monitors use an On Demand regulator
to expose the span gas to the monitor. (see section 6.1.2)
5. Only expose the monitor to span gas blends that consist of Oxygen and
Nitrogen only. Do Not expose the monitor to any combustible gas, i.e.,
Methane, Hydrogen, etc. Exposure to combustible span gases can damage the
oxygen zirconium sensor cell.
6. Do not expose the Oxygen monitor to silicone, Freon, or corrosive
compounds. They can cause a loss of sensitivity and damage the sensor.
7. When using the Air Check O2 Monitor in wash down areas make sure you
orient the filter with the drain opposite the water flow. (see section 3.2.4)
8. NOTE: If using longer lengths of sample tubing, the water filter must be
located at the end of the sample line to work properly.
9. The Factory Password for entering the menus is 557
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Table of Contents
1: Introduction ………………………………………………………………………………………………………2 1.1 Key Features
………………………………………………………………2 1.2 Component identification …………………………………………….3
2: Specifications…………………………………………………………………………………………………….7 2.1 Performance
Specifications ………………………………………….7 2.2 Gas Detection
System………………………………………………….7 2.3 Signal Outputs ……………………………………………………………7 2.4
Electrical Requirements……………………………………………….7 2.5 Physical Characteristics
……………………………………………….7 2.6 System Default Factory Settings …………………………………..8
3: Installation ………………………………………………………………………………………………………..9 3.1 Site
Requirements……………………………………………………….9 3.2 Mounting……………………………………………………………………9
3.3 Wiring ……………………………………………………………………..13 3.4 Initial Startup
……………………………………………………………13
4: Normal Operation …………………………………………………………………………………………….15 4.1 Signal Outputs
………………………………………………………….15 4.2 Instrument Faults ………………………………………………………15 4.3
Routine Maintenance Schedule …………………………………..16 4.4 Loss of Power
Indicator……………………………………………..16 4.5 Alarm Reset ……………………………………………………………..16
5: Air Check O2 Monitor Programming ………………………………………………………………….18 5.1 Joystick
Operation …………………………………………………….18 5.2 Program Flowchart ……………………………………………………19
5.3 Entering the Password ……………………………………………….23 5.4 Changing the User Password
………………………………………24 5.5 Entering the Menus……………………………………………………27 5.5.1 Set
4-20mA Loop ……………………………………………..27 5.5.2 Set Formats ………………………………………………………29
5.5.3 Set Alarm Threshold Polarity ……………………………..31 5.5.4 Set Latching
……………………………………………………..33 5.5.5 Resetting a Latching Alarm ………………………………..36
5.5.6 Set Alarm Delay ……………………………………………….36 5.5.7 Set Zero Suppression
…………………………………………37 5.5.8 Set Alarm Thresholds ………………………………………..37 5.5.9 Set
Alarm Hysteresis …………………………………………39 5.5.10 Set Sensor
Adjust…………………………………………….40 5.5.11 Main Operation Mode………………………………………41
6: Maintenance & Cell Verification ……………………………………………………………………….42 6.1 Sensor
Verification ……………………………………………………42 6.2 Sensor Verification
Procedure…………………………………….43
7: Appendix ………………………………………………………………………………………………………..46
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1: Introduction
The Air Check O2 water resistant monitor is a self-contained Oxygen deficiency
detection system suitable for remote sampling of confined spaces that require
daily wash-downs. It’s a compact gas monitoring system that’s ideal for the
continuous monitoring of inert gas storage areas, confined spaces, and other
locations where low oxygen levels may pose a hazard to personnel. Unlike
electrochemical sensor cells the Air Check O2 zirconium cell provides stable
oxygen readings even in areas where temperature and humidity levels are
changing. The PureAire Air Check O2 Deficiency Monitor is suitable for either
indoor or outdoor use. Factory calibrated against a NIST traceable reference
standard and UL, CUL and Ce approved.
The heart of the monitoring system is a long-lasting zirconium sensor, which
responds to low oxygen conditions within seconds and provides accurate
measurements over a wide temperature and humidity range. The zirconium O2
sensor cell will operate continuously for 8 or more years and requires an
absolute minimum of maintenance. There are no zero or span calibration pots to
adjust and when compared to disposable type sensors, our long-life zirconium
O2 sensor can save up to hundreds of dollars in annual maintenance.
Ideal for continuously monitoring oxygen levels in food processing areas where
inert gases are used in freezing tunnels, the Air Check water resistant O2
monitor does not drift or loose sensitivity when the weather or temperature
changes. The electronics are housed in a 4X IP65 water resistant housing
capable of withstanding water projected from a nozzle.
Each system consists of a long-life zirconium oxide sensor cell and three-wire
transmitter. The Air Check O2 monitor may be used as a stand-alone gas
detector, linked to optional PureAire single and multipoint controllers, or
connected to your own centralized control and surveillance system. This manual
covers the installation, operation, and maintenance of the Air Check water
resistant O2 deficiency monitor.
1.1 Key Features
The Air Check O2 monitor incorporates several user-friendly features designed
to simplify installation, operation, and maintenance.
1.1.1 Long Life Zirconium Oxide O2 Sensor The system’s O2 sensor cell has a
life of well over 8 years of continuous operation. Unlike concentration O2
cells, PureAire’s exclusive zirconium oxide sensor cell does not need an
oxygen reference gas for proper operation. The Air Check O2 monitor can detect
low oxygen levels in confined spaces and process tools without the need of a
reference gas.
1.1.2 Smart Electronics The Air Check O2 monitor incorporates a special
electronic circuit that continuously monitors sensor operation. With the
built-in alarm relay, any cell degradation or complete failure will
immediately be detected. This smart circuitry alerts the user to sensor faults
and other electrical problems that may interrupt surveillance through the
standard mA signal output signal and through the fault relay.
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1.1.3 Calibration
The Air Check O2 monitor incorporates a stable zirconium oxide sensor that
rarely requires adjustment. Changing barometric pressure changes or changes in
temperature and humidity do not affect the zirconium oxide oxygen cell. The
earth is a wonderful source of calibrated oxygen at 20.9%, therefore under
ambient conditions, visual verification of the Air Check O2 monitor to 20.9%
oxygen is easily performed. There are no zero or span pots to adjust. The O2
monitor only requires periodic testing with nitrogen to verify the cells
response to low oxygen levels. See Section 6.2 for the testing procedure to
nitrogen.
1.2 Component Identification
1.2.1 Front View Exterior
Digital Display Joystick
Front Cover
Front panel fastening screws (2 ea.)
Front Cover Fasteners (4ea.)
Sample Exhaust
Cable Strain Relief
Alarm and Fault Relays
Mounting Feet (4ea.) not shown)
Sample Inlet
1. Front Cover — This is a removable, waterproof cover that protects the
interior of the transmitter. It fastens through 4ea. captive screws
2. Joystick — Used for selecting and adjusting the built-in menus. The Air
Check O2 Sample draw monitor has dual level user selectable alarms.
3. Digital Display — This displays the Oxygen levels in percentage. The
normal oxygen level on earth is 20.9%
4. Front Cover Fasteners– The Air Check O2 Sample draw monitor has 4ea.
captive screws to remove the front window from the base unit.
5. Sample Inlet — This inlet permits the flow of oxygen to enter the sensor
cell.
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6. Sample Exhaust — This permits the flow of oxygen to exit the enclosure. 7.
Cable strain relief — This is the sealed opening in the transmitter housing
for connecting the input power, 4-20 mA output and relay wiring.
1.2.2 Front View with front cover removed
Sample pump
Joystick
Oxygen sensor assembly
Retaining Screws for electronics panel
Alarm Relay LED’s
Fault
Alarm 1
Alarm 2
8. Sample Pump — Used to bring in a sample to the oxygen cell. Flow rate is
preset at the factory. Flow rate is continuously protected with a built-in
flow sensor. See Section 4.2: Instrument Faults
9. Oxygen Sensor Assembly — A zirconium oxide sensor, which detects and
measures the level of oxygen. When exposed to oxygen, the sensor outputs an
electrical signal proportional to the actual concentration of oxygen.
10. Front Panel Retaining Screws — These captive screws are used to mount the
display front panel and O2 electronics to the enclosure. NOTE: When
unfastening the front panel electronics, apply upwards pressure on the back of
the front panel to release the captive screws.
11. Alarm Indicators — 3 multi-colored LED indicators for showing: Alarm
level 1 Orange LED Alarm level 2 Red LED Fault Alarm Yellow LED
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O2 water resistant monitor front cover removed
Alarm and Fault Relays & Terminal blocks Relays Flow Sensor
O2 Sensor connector Sample pump connector
Sample Pump
1.2.3 Transmitter Interior
2. Sensor cell connector
1. Power Analog output Terminal Block
Common Common mA output + 24 VDC + 24 VDC
3. PTC Resettable Fuse
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1. Power Analog Terminal Block — This terminal block is where the 24VDC power
and 4-20 mA analog output connection is made.
2. Sensor Cell Connector — This connector is where the Oxygen sensor cell is
connected. NOTE: Never connect the oxygen sensor to this connector while the
monitor is powered. This will damage the oxygen sensor
3. PTC Resettable Fuse — The PCB is protected with a PTC Fuse that is
resettable and Never needs to be replaced. If it trips, you will need to turn
power off to the monitor. When power resumes the fuse will reset.
1.2.4 Alarm Relay Board
(Identification legend is located between the relay and connector)
Relay 2 Relay 1 Fault Relay NC C NO NC C NO NC C NO
Remote Reset
Flow Sensor
Pump Connector
Sensor cell Connector
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2: Specifications
NOTE: For our continual product improvement, all specifications are subject to
change without notice.
2.1 Performance Specifications
Sensor Type:
Long Life Zirconium Oxide Sensor Cell 0-25%
Response Time: Within 2 seconds of any change in O2.
Repeatability:
± 2% of reading
Fault Indicators:
Loss of VDC power (analog signal drops to 0 mA). Sensor cell failure: Fault relay activated
Operating Temp: -40° to 104°F (-40° to +40°C); consult PureAire for lower or higher temperature
Humidity:
0 to 100% RH; IP65 water resistant enclosure
Environment:
Altitude 2000 m, PSU only UL spec. Pollution Degree 3
Sampling distance: Max distance 100 feet, (33M)
UL / CUL listing: Measuring Equipment E363306
Ce
EN 61000-3-2:2006 EMC, EN 61000-3-3:2008 EMC, EN61010-1-3-2013 LVD
2.2 Gas Detection System
Type:
Long Life Zirconium Oxide Sensor Cell, Range 0-25%
Sensor Life:
8-10 years under normal conditions.
Transmitter:
Microprocessor electronics with built-in 3-digit backlit LCD display
Joystick operated menus
2.3 Signal Outputs
Local Display:
Digital display calibrated for Oxygen. The range is stated on the model label and also can be accessed via the joystick on the front panel. In the measurement mode pushing the joystick down will scroll the gas and range on the display. Push the joystick down again to stop the scrolling and display the gas again.
Analog Output:
DC 4-20 mA
Relay Output:
Dual level user selectable alarm relays and one fault relay
Rated, 2amps @ 24VAC or 24VDC
2.4 Electrical Requirements
Power: Consumption:
24 VDC external power. A regulated 24VDC power supply is required. Approximately 300mA
2.5 Physical Characteristics
Dimensions:
7.0 (W) x 5.0 (H) x 5.0(D) inches; 178 x 127 x 127 mm
Weight:
4.0 pounds (2 kg)
Enclosure Type:
Polycarbonate wall mount IP65 water resistant. Not intended for explosive atmospheres or electrically classified areas.
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2.6 AirCheck O2 System Default Factory settings
The Air Check O2 water resistant monitor is shipped with factory defaults for
the alarm relay settings. The following are the factory defaults:
Menu Function
0B
Set 4-20mA loop
Set Formats LED and alarm relay State ** Set Alarm Threshold Polarity
Set Latching
Alarm Delay Zero Suppression Set Alarm Thresholds Set Alarm Hysteresis
Sensor Adjustment
Manage Passwords
Factory Default
1B
The mA output is set at the factory using a calibrated Fluke meter.
Alarm 1 = Normal Alarm 2 = Normal Fault = Normal
Alarm 1 = Inverted Alarm 2 = Inverted Audio = Inverted
Alarm 1 = Non-latching Alarm 2 = Non-latching Audio = Non-latching
Alarm = 5 seconds
000 = 0.00%
Alarm 1 = 19.5 % Alarm 2 = 18.0 % Audio = 19.5% Alarm 1 = 0.0 % Alarm 2 = 0.0
% Audio = 0.0 % No factory default
Factory default is 557
Menu Defined
2B
Use this function to adjust the Oxygen monitors 4mA, (Zero) and 20mA, (Span)
to your PLC or distributive control system. Do you want the relays to
energize, (normal) or de-energize, (fail safe) when the alarm activates? Do
you want to alarm at a level higher, (normal) or lower, (inverted) than the
alarm threshold? Do you want the alarm to automatically reset? (non-latching)
or do you want to manually reset the alarm? (latching) How long do you want to
wait until the relay alarms activate? This function is Not Enabled on the
Oxygen monitor. At what level do you want to alarm?
For use when using the O2 monitor for control or valves and process. See
Section 5.5.9 For use when dynamically gas calibrating the Oxygen monitor to a
known span gas. See Section 6.2 For use when changing the password from
factory default to a new password of your choice.
NOTE: The built-in relay settings may be changed by the user in the field. Refer to Section 5.4.2
- NOTE: The Audio alarm feature is optional.
** NOTE: The LED indicators on the front panel are connected directly to the alarm relays.
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3: Installation
3.1 Site Requirements
The Air Check O2 monitor enclosure should be mounted in an area free of
vibration and electrical noise or interference. If possible, avoid areas with
high temperatures.
WARNING: The Air Check O2 monitor is not designed for installation in
hazardous areas. Consult PureAire for information on enclosures for use in
hazardous environments.
3.2 Mounting
3.2.1 Transmitter Enclosure The Air Check O2 monitor is designed primarily for
wall mounting and should be installed at a height convenient for operation,
maintenance, and viewing of the instrument display.
3.2.2 Air Check O2 monitor The transmitter and sensor should be installed in a
location where gas leaks are likely to occur or where released gases may
accumulate. It should be mounted no closer than 12 inches above floor level.
Airflow within the monitored area, the characteristics of the gas (lighter or
heavier than air), and the position of workstations and personnel should all
be considered in determining the most suitable installation location. NOTE:
Leave clearance room on the bottom of the Oxygen monitor for the inlet water
filter, which adds an additional 12 inches.
7.0″
12″ (approx.)
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3.2.3 Enclosure Mounting Feet
Mounting Feet Can be oriented in any direction
Feet can also be removed for mounting the O2 monitor flush with a wall or
other surface
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3.2.4 Air Check Sample Inlet Filter
To protect the pump from water, a special filter is supplied with the monitor.
On installation, attach the water filter to the sample inlet by pushing the
filter into the ¼” tube compression fitting. Aligning the arrow, (printed on
the filter) towards the monitor. The filter pulls air from both vertical and
horizontal tubes. Never connect any sampling tubing to either tubing ports.
When sampling remote, ALWAYS locate this filter at the end of the sample line.
Sample air can enter from either port. This is the reason the water filter
must be located at the end of the sample line.
The Air Check O2 Sample Draw monitor has an internal sample flow rate that is
programmed at the factory and cannot be changed in the field. A flow sensor on
the relay board continually monitors flow rate. When a loss of flow is
detected, a signal is sent to the fault relay and the front mounted LED will
activate. Sample flow to the monitor is continuously monitored and controlled
by the flow control microprocessor. NOTE: If using longer lengths of sample
tubing, the water filter must be located at the end of the sample line to work
properly.
NOTE: If the sample line is blocked, the fault indicator will illuminate, and
the pump will accelerate to try and reestablish the proper flow rate. If the
line is cleared, the pump will speed and slow down and the fault light will
turn off when the flow rate is back to factory setting. The “Flow Fault”
message can be cleared by pushing the joystick down
Depending on the environment, replacement of this filter should be performed
every 12 months. In dusty environments, a standard filter (p/n 23102) should
be added at the monitor. If the filter becomes completely blocked, the
internal flow sensor will detect the loss of flow and activate the fault relay
and LED. Order water filter p/n 90179
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“Dirty” Environment
**NOTE: PureAire recommends the use of polypropylene sample tubing with the
dimensions of 1/4″ OD by 3/16″ ID. The total length of tubing should not
exceed 100 feet.
Photo shown is a waterproof monitor located at the risk site.
If any length of sample tube is needed to sample remote, the water filter must
be located at the end of the sample tubing.
¼” tube push to connect fitting ** Water Sample filter p/n 90179
Sample air can enter from either port. This is the reason the water filter
must be located at the end of the sample line.
NOTE: When used in wash down areas, the water filter drain must be oriented
opposite the water flow. (i.e., orient the drain towards the back of the
monitor to prevent water from building up inside the drain.)
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3.3 Wiring
The Air Check O2 monitor requires a single, 3-wire shielded cable for analog
output and 24 VDC power input. A three-wire shielded cable; 3-conductor, 18
AWG stranded General Cable E2203S.30.860, or equivalent is recommended for the
connection. The analog out and VDC power in connections are made on the
terminal block inside the transmitter housing.
These connections are made as follows:
– Common – Common mA* 4-20mA signal output to PLC + 24VDC Power + 24VDC Power
Identification Legend
PureAire provides the plug-in power supply
- Caution: DO NOT connect to a powered current loop receiver. The Air Check
Oxygen monitor supplies the current loop power.
33.4.3 Initial Startup
Once installation of the gas detector has been completed, it is ready for startup. The following procedures should be performed before putting the instrument into operation:
1. Check the integrity of all wiring. 2. Apply 24 VDC power to the Power Supply PCB board. The sample pump
will activate. Also, the digital display second line will quickly display the DTM, (digital transmitter module) serial number and Software version.
NOTE: To display the DTM numbers push the joystick to the left. To display the gas and range push the joystick down and the gas and range will continuously scroll. To stop the scrolling, push the joystick down.
The instrument should now be powered up. Upon power up, the Air Check O2 monitor LCD displays the PureAire logo and then starts a 4-minute, (240 second) count down as the current to the zirconium oxide O2 sensor stabilizes. The monitor will output a 4 mA signal during the entire warm-
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up period. After the countdown, the oxygen sensor will continue to reach its
operating temperature for approximately 30 minutes and the reading displayed
will slowly increase to ambient. Do not make any adjustments to the reading
until after the monitor has been powered for at least an hour.
Oxygen 239 WARM
NOTE: Immediately after the countdown, the monitor will display “FLOW FAILURE:
OUT OF RANGE” on the top line and disappear. This is a fault history message
only and is generated on start-up to verify the integrity of the system. The
message will automatically clear and “Oxygen” will display on the top line and
the “20.9%” reading will display on the bottom line. If the fault is still
present, the actual fault code will display on the bottom line. The instrument
should now be operating properly and is ready for monitoring.
NOTE: The Air Check O2 monitor’s reading may be adjusted to the ambient oxygen
level. See section 6.1 for instructions on adjusting. Pump Adjustment The Air
Check Sample Draw O2 monitor has a built in digitally controlled flow
controlled sample pump. The pump flow is set at the factory and should not
require adjustment. It has a range to accommodate tubing lengths of 3 feet to
over 100 feet. If flow adjustment is necessary, please contact PureAire. NOTE:
Normal flow rate is 0.25 liters per minute. (250cc/min)
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4: Normal Operation
The Air Check O2 monitor is a single point monitor designed for the continuous
detection and measurement of ambient oxygen concentration levels.
4.1 Signal Outputs
The Air Check O2 monitor outputs a continuous 4-20 mA analog signal
proportional to the measured concentration of oxygen. 4 mA represents 0% O2
and 20 mA represents 25% O2 which is the full range. In the event of a system
fault, a specific factory defined code will be displayed on the local digital
display. This code will indicate the exact nature of the system fault. A few
codes are listed below.
CAUTION: DO NOT connect to a powered current loop receiver. The Air Check Oxygen monitor supplies the current loop power.
4.2 Instrument Faults
The Air Check O2 monitor incorporates a number of self-checking features to
ensure reliable operation. In the event that a fault condition is detected,
the analog output signal is altered: A few common error codes are displayed in
the following table:
Condition
**Supply Voltage Out of Range Fault code 16
Transmitter cable cut
O2 Cell current fault Fault Code 128
Analog Signal Analog output drops to 2 mA
Analog output drops to 0 mA Analog output drops to 2 mA Fault Relay activates
O2 System Warm Up
Analog output drops to 2 mA Fault Relay activates and turns off when system is in the Oxygen operation mode
O2 Cell voltage fault Fault Code 64
Analog output drops to 2 mA Fault Relay activates
No Flow to the Oxygen sensor Fault Code 32
EEPROM Fault 08
Analog output drops to 2 mA Fault Relay activates
Analog output drops to 2mA
NOTE: All system faults are displayed on the front panel. Each fault has it’own specific code to identify the specific problem. Please contact PureAire whenever a fault is displayed.
** When using your own power supply please ensure that the voltage is regulated to 24VDC +/- 0.5 volts. If the voltage is too low or high you will activate a “Supply Voltage Out of Range fault and disable the monitor.
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NOTE: If a Fault condition clears itself, (Yellow LED is no longer
illuminated) The Fault message will continue to scroll until manually cleared.
To clear the fault message, push the joystick down (- Minus)
4.3 Routine Maintenance Schedule
Continuous gas detection systems depended upon to measure and detect hazardous
gas leaks in the workplace requires periodic maintenance to ensure proper
operation. The frequency with which this routine maintenance is required
depends on the environment. The following table is intended to serve as a
general guideline for routine maintenance. The conditions in your particular
application, as well as your organization’s maintenance policies, will
ultimately determine the best routine maintenance schedule for your equipment.
Routine Visual Checks
Items to check
Condition / status when operating properly
Check for power and proper operation
Unit should be outputting a 17.34 mA signal when the oxygen level is at 20.9%.
The LCD digital display should also indicate 20.9% 02 when the oxygen is at
ambient levels.
4.3.2 Recommended Routine Maintenance Schedule
Routine Visual Checks
Every 6 – 12 months
Sensor Verification with nitrogen
Every 6 – 12 months**
** The ambient oxygen level is 20.9%; therefore, under ambient conditions
visual verification of the Air Check O2 monitor to 20.9% oxygen is easily
performed. The O2 monitor only requires periodic testing with nitrogen to
verify the cells response to low oxygen levels. See Section 5.5.10 for how to
make minor adjustments.
4.4 Loss of Power Indicator
In the event the Air Check O2 monitor loses 24VDC power, the 4-20 mA analog
output signal drops to 0mA. The LCD display will also display a blank screen.
4.5 Alarm Reset
It the Air Check O2 monitor is supplied with the optional alarm relays,
whenever the monitors alarms are activated, the built-in alarm relays, panel
mounted LED’s and optional audio horn will also activate. When the relay
settings are non-latching, the alarm relays, LEDs, and horn will automatically
reset. If the relay settings are latching, then a manual reset of the alarms
are required. Resetting the alarms can be performed through use of the
joystick or using the remote reset function.
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Joystick You must enter the password to enter the reset function. After the
password is entered and accepted, push the joystick in; (enter) to reset the
alarms. Remote Reset Refer to section 1.2.4. for location on PC board. The
alarm relay board has a two-pin connector for wiring to a remote switch. When
connected to a switch, this remote reset will bypass the joystick and a
password will not be needed to reset the alarms.
NOTE: The oxygen levels must recover above the alarm thresholds before the
horn can be reset from the remote reset switch or joystick.
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5: Air Check O2 Monitor Programming
The Air Check O2 Deficiency Monitor is supplied with user selectable settings
to adjust the alarm settings, 4 and 20mA output and minor sensor adjustments.
The settings are arranged in menus that are accessed by moving the joystick.
To access the menus a factory set password is used. NOTE: The Air Check O2
Deficiency Monitor will continuously monitor oxygen while accessing the menus.
The alarm, fault relays and mA output are all active and online while making
any changes to the menus.
5.1 Joystick Operation
The Air Check O2 monitor uses an 8-position joystick with a center pushbutton
for selecting menus and changing values. The joystick is programmed to
standard protocol as follows:
NOTE: The joystick has a built-in delay to prevent accidental tampering of the
menus. deliberate entries are required.
CAUTION: Only qualified personnel should perform programming, maintenance, and
sensor verification
+ Plus
Previous
Next
– Minus
Plus Pushing the joystick in this direction increases the value Minus
Pushing the joystick in this direction decreases the value Next Pushing the
joystick in this direction moves you to the next level of the menu hierarchy.
Previous Pushing the joystick in this direction takes you out to the last
level of menu hierarchy. Enter Pushing the joystick directly in the center
enters the information into the microprocessor
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5.2 Program Flowchart
Oxygen 20.9%
Enter Password
557
PassCode OK
PassCode OK
Set 4-20mA loop
Set 4mA Zero
255
Set 20mA Span
Force loop
255 Not available
NOTE: All numerical values shown are only examples and are not Factory Defaults
Set Formats
Format Relay 1
Format Relay 2
Format Fault Relay
Normal Invert Normal Invert
Normal Invert
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PassCode OK
Set Alarm Threshold
Polarity
Set Alarm 1 Polarity
Set Alarm 2 Polarity
Normal Invert
Normal Invert
Set Latching
Set Audio Alarm Polarity
Set Latching Relay 1
Set Latching Relay 2
Set Latching Audio
Not available
Nonlatch Latch
Nonlatch Latch
Not Available
NOTE: All numerical values shown are only examples and are not Factory Defaults
Alarm Delay
005
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PassCode OK
Zero Suppressio
000 *
- NOTE: Zero
suppression function is not available for Oxygen
Set Alarm Thresholds
Set Relay 1 Alarm
19.5%
Set Relay 2 Alarm
18.0%
Set Alarm Hysteresis
Set Audio Alarm
Set Alarm 1 Hysteresis
Sensor Adjustment
Set Alarm 2 Hysteresis
Set Audio Alarm
Hysteresis
Set sensor span
19.5% 0.0%
0.0%
NOTE: All numerical values shown are only examples and are Not Factory Defaults
0.0%
055
Set Module zero
Not Available **
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PassCode OK
Manage Passwords
Enter New User
Password
Enable User Password
Reset User Password
A
Enabled Disabled Not Available
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5.3 Entering the Password
The Air Check Oxygen monitor is supplied with a factory set password to prevent unauthorized access to the menus. The Password is 557. The following explains how to enter the password.
1. Push the joystick once to the right. Enter Password will scroll on the first line of the digital display. The second line will still display the current oxygen level.
..Enter password… 20.9 %
2. Push the joystick again once more to the right to enter the input screen.
The letter A will appear and flash. A 20.9%
NOTE: The display has characters that start with A through Z and 0 through 9.
Pushing the joystick up or down will permit you to scroll through the
alphanumeric characters.
3. Push the joystick up or down to enter the first digit. The display is an
alphanumeric display and toggles from A through Z followed by 0 to 9. The
character to be entered will flash.
5 20.9%
4. Push the joystick again to the right to select the second entry. Push the joystick up or down to select the second digit. The character being entered will flash and the first character entered will remain lit. 55 20.9%
5. Push the joystick again to the right to select the third entry. Push the
joystick up or down to select the third and final digit. The character being
entered will flash and the first and second characters entered will remain
lit. You are now ready to enter the 3-digit password.
557 20.9%
6. Push the joystick in the center to enter the password. If you entered it correctly the display will
scroll Password OK.
…PassCode OK……
20.9%
NOTE: If an incorrect password has been entered, the display will indicate Password Failed. Push the joystick to the left to access the monitoring mode. From this mode you can reenter the password again.
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5.4 Changing the User Password
The Air Check Oxygen monitor is supplied with a factory set password to
prevent unauthorized access to the menus. The user can change this password
and the following explains how to change the password.
1. Push the joystick down to access the Manage Passwords Menu. Manage
Passwords will scroll on the first line of the digital display. The second
line will still display the current oxygen level. ..Manage Passwords… 20.9%
2. Push the joystick to the right to enter the input screen. Enter New User
Password will scroll on the first line of the digital display
…Enter New User Password… 20.9 %
3. Push the joystick to the right to enter the input screen. The letter A
will appear and flash.
A 20.9%
NOTE: The display has characters that start with A through Z and 0 through 9.
Pushing the joystick up or down will permit you to scroll through the
alphanumeric characters.
4. Push the joystick up or down to enter the first digit. The display is an
alphanumeric display and toggles from A through Z followed by 0 to 9. The
character to be entered will flash.
2 20.9%
5. Push the joystick again to the right to select the second entry. Push the
joystick up or down to select the second digit. The character being entered
will flash and the first character entered will remain lit.
25 20.9%
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6. Push the joystick again to the right to select the third entry. Push the
joystick up or down to select the third and final digit. The character being
entered will flash and the first and second characters entered will remain
lit. You are now ready to enter the 3-digit password.
253 20.9%
7. Push the joystick in the center to enter the password. This will display
the next command, Re-Enter New Password
…Re-Enter New Password… 20.9 %
8. Push the joystick to the right to enter the input screen. The letter A
will appear and flash.
A 20.9%
9. Push the joystick up or down to enter the first digit. The display is an
alphanumeric display and toggles from A through Z followed by 0 to 9. The
character to be entered will flash.
2 20.9%
10. Push the joystick again to the right to select the second entry. Push the
joystick up or down to select the second digit. The character being entered
will flash and the first character entered will remain lit.
25 20.9%
11. Push the joystick again to the right to select the third entry. Push the
joystick up or down to select the third and final digit. The character being
entered will flash and the first and second characters entered will remain
lit. You are now ready to enter the 3-digit password.
253 20.9%
12. Push the joystick in the center to enter the password. If you entered it
correctly the display will scroll “New Password Entry OK”.
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…New Password Entry OK… 20.9%
NOTE: If on the second entry the password entered was different from the
first, the display will take you back to the “Re-enter Password Screen”. You
will need to repeat steps 2 through 11. If you do not enter the password
correctly, the monitor remembers the last password that was properly input.
If you misplace or loose your password, contact PureAire with the monitors
DTM# for instructions on recovering your password. The DTM# is displayed by
moving the joystick to the left.
5.4.1 Enable User Password
This menu permits the user to activate or disable the password function on the
Oxygen monitor. Push the joystick down. “Enable User Password” will scroll on
the first line of the digital display
…Enable User Password… 20.9%
Push the joystick right to display the status. If enabled it will display
“Enabled”
Enabled 20.9%
Push the joystick up or down to change the status. Once enabled or disabled is
selected, Push the joystick in the center to enter the new status. If
correctly entered the display will scroll “Enable User Password”
…Enable User Password… 20.9%
5.4.2 Reset User Password This menu permits you to reset the password back to
557, as set at the factory.
…Reset User Password… 20.9%
Push the joystick right to display the menu, “Reset to factory Default”.
…Password Reset to factory Default… 20.9%
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Push the joystick in, (like a doorbell) to reset the password back to 557.
Push the joystick left 4 times to go back to the measuring mode.
NOTE: If you lose your password please contact PureAire with your
se5r.i5alEnunmtebreirnogr DthTeMMneunmubesr
Oxygen 20.9%
5.5 Entering the Menus
The Air Check O2 monitor is supplied with main menus with sub menus to adjust
mA outputs, alarm relay settings, sensor adjustments and zero suppression for
toxic and corrosive gas sensor cells.
5.5.1 Set 4-20mA loop
.Set 4-20mA loop.. 20.9%
This main menu will permit the adjusting of the 4mA and 20mA output from the
Air Check O2 Monitor. It also provides a function that will send an actual
output between 4mA and 20 mA to test any remote control and alarm system
attached to the O2 monitor.
NOTE: To read the mA output, Air Check O2 monitor must either be connected to
a remote PLC controller or SCADA system. You can also connect the Air Check O2
monitor to a voltmeter to read the mA output. Please consult PureAire for more
information.
From this main menu, pushing the joystick to the right will select the sub
menu and the digital display will scroll the following:
..Set 4mA zero… 20.9%
This is the menu at which to adjust the 4mA output being sent from the Air
Check O2 Monitor.
To change this value, push the joystick right to display the 4 mA setting. The
display will indicate a value between 0 and 255 counts. Pushing the joystick
up increases the value and pushing the joystick down decreases the value. The
4mA output being sent from the Air Check O2 monitor will change as the number
on the digital display changes. Press ENTER to accept the value.
255 20.9%
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Push the joystick to the left brings you back to the pervious Main menu. The
digital display will scroll the following:
…Set 4mA zero….. 20.9%
Push the joystick down to access the next sub menu; Set 20mA Span will scroll.
…Set 20mA Span… 20.9%
This is the menu at which to adjust the 20mA output being sent from the Air
Check O2 Monitor.
To change this value, push the joystick right to display the 20mA span
setting. The display will indicate a value between 0 and 255 counts. Pushing
the joystick up increases the value and pushing the joystick down decreases
the value. The 20mA output being sent from the Air Check O2 monitor will
change as the number on the digital display changes. Press ENTER to accept the
value.
255 20.9%
Push the joystick to the left brings you back to the pervious Main menu. The
digital display will scroll the following:
…Set 20mA span….. 20.9%
Push the joystick down to access the next sub menu; Force loop will scroll.
….Force Loop…. 20.9%
NOTE: The Force Loop function is not available on the Air Check O2 monitor. It
was designed for toxic and corrosive gases.
This is the sub menu is only used on PureAire’s toxic and corrosive monitors.
…Not Available.. 20.9%
Push the joystick to the left brings you back to the pervious menu. The digital display Will scroll the following:
…Force Loop….. 20.9%
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5.5.2 Set Formats
This is the menu at which to adjust the relay states for the two gas alarm
relays and the individual instrument fault relay.
NOTE: The O2 system must have the relay module installed to access this menu.
If no relay module is installed the display will indicate N/A, (not available)
Push the joystick down to access the next main menu, Set Formats. The display
will scroll the following:
…Set Formats… 20.9%
This menu will permit the setting of the two alarm relays and the fault relay
settings from normally de-energized state, Normal, to normally energized
state, Inverted.
From this main menu, pushing the joystick to the right will select the sub
menu and the digital display will scroll the following:
..Format Relay 1… 20.9%
This is the menu at which to adjust the first level alarm relay state on the
Air Check O2 Monitor.
To change this value, push the joystick right to display the relay state. The
display will Indicate INVERT. Pushing the joystick down will change the relay
state from INVERT to NORMAL. Press ENTER to accept the value.
INVERT 20.9%
NORMAL 20.9%
After entering the relay state, the display will default back to the Set
Formats menu. The display will scroll the following:
..Set Formats… 20.9%
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From this main menu, pushing the joystick to the right will select the sub
menu and the digital display will scroll the following:
..Format Relay 1… 20.9%
Push the joystick down to access the next main menu, Set Formats. The display
will scroll the following:
… Format Relay 2.. 20.9%
This is the menu at which to adjust the second level alarm relay state on the
Air Check O2 Monitor. To change this value, push the joystick right to display
the relay state. The display will Indicate INVERT. Pushing the joystick down
will change the relay state from INVERT to NORMAL. Press ENTER to accept the
value.
INVERT 20.9%
NORMAL 20.9%
After entering the relay state, the display will default back to the Set
Formats menu. The display will scroll the following:
..Set Format … 20.9%
From this main menu, pushing the joystick to the right will select the sub
menu and the digital display will scroll the following:
..Format Relay 1… 20.9%
Push the joystick twice to select the fault relay to be adjusted. The display
will scroll: Format Fault Relay.
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..Format Fault Relay… 20.9%
This is the menu at which to adjust the fault alarm relay state on the Air
Check O2 Monitor.
To change this value, push the joystick right to display the relay state. The
display will Indicate INVERT. Pushing the joystick down will change the relay
state from INVERT to NORMAL. Press ENTER to accept the value.
INVERT 20.9%
NORMAL 20.9%
After entering the relay state, the display will default back to the Set
Formats menu. The display will scroll the following:
..Set Formats… 20.9
5.5.3 Set Alarm Threshold Polarity
Alarm Threshold Polarity determines if an alarm concentration is set above or
below a threshold value. For example, if an alarm of 19.0% for Oxygen is
selected, the Alarm Threshold Polarity must be set to Invert for the monitors
alarm to activate when the reading goes below 19.0%. For toxic and corrosive
gases selecting a Normal setting for the Alarm Threshold Polarity means that
the system will alarm when the gas concentration exceeds, goes above, an alarm
set point. This menu will permit the selection of the alarm polarity. To
access this menu from the “Set Formats” menu, push the joystick down to
display the Set Alarm Threshold Polarity adjustment menu. This will scroll on
the digital display.
..Set Alarm Threshold Polarity.. 20.9%
Push the joystick right to access the first sub menu; Set Alarm 1 Polarity
will scroll on the display. This is the menu at which to adjust the first
level alarm polarity state on the Air Check O2 Monitor.
..Set Alarm 1 Polarity… 20.9%
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To change this value, push the joystick right to display the relay state. The
display will Indicate INVERT. Pushing the joystick down will change the relay
state from INVERT to NORMAL. Press ENTER to accept the value.
INVERT 20.9%
NORMAL 20.9%
After entering the relay state, the display will default back to the Set Alarm
1 Polarity menu. The display will scroll the following:
..Set Alarm Polarity.. 20.9%
Push the joystick down to access the next sub menu; Set Alarm 2 Polarity will
scroll on the display. This is the menu at which to adjust the second level
alarm polarity state on the Air Check O2 Monitor.
..Set Alarm 2 Polarity .. 20.9%
To change this value, push the joystick right to display the relay state. The
display will Indicate INVERT. Pushing the joystick down will change the relay
state from INVERT to NORMAL. Press ENTER to accept the value.
INVERT 20.9%
NORMAL 20.9%
After entering the relay state, the display will default back to the Set Relay
2 Alarm Threshold menu. The display will scroll the following:
..Set Alarm 2 Polarity.. 20.9%
Push the joystick down to access the next sub menu; Set Audio Alarm Polarity
will scroll on the display. This is the menu at which to adjust the second
level alarm polarity state on the Air Check O2 Monitor.
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..Set Audio Alarm Polarity… 20.9%
NOTE: The O2 system must have the audio alarm option module installed to
access this menu. If this option is installed the display will indicate N/A,
(not available)
NOTE: The optional built-in horn is designed to operate in only one alarm
mode. It will activate in either a decreasing alarm or an increasing alarm
mode only. The horn activation is immediate any time an alarm threshold is
exceeded.
To change this value, push the joystick right to display the relay state. The
display will Indicate INVERT. Pushing the joystick down will change the relay
state from INVERT to NORMAL. Press ENTER to accept the value.
INVERT 20.9%
NORMAL 20.9%
AUTO 20.9%
Auto Mode – The auto mode is used when you wish the horn to activate at the
same time the relays activate. In the Normal or Inverted Mode, the horn
immediately activates any time the alarm thresholds are exceeded. To activate
the horn when the relays activate, choose the AUTO mode.
After entering the relay state, the display will default back to the Set Audio
Alarm Polarity menu. The display will scroll the following:
..Set Audio Alarm Polarity… 20.9%
5.5.4 Set Latching
This is the menu at which to adjust the relay alarm state for the two gas
alarm relays and the individual instrument fault relay. The selection permits
setting the relays to a latching or non-latching state. In a latching state,
the relay will remain activated until the user manually selects the Enter Key.
In a non-latching state, the alarm relay will automatically reset once the gas
concentration has returned to 20.9% for oxygen.
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NOTE: The O2 system must have the relay module installed to access this menu.
If no relay module is installed the display will indicate N/A, (not available)
.Set Latching… 20.9%
This menu will permit the setting of the two alarm relays and the fault relay
settings from a latching to a non latching state when they are activated.
From this main menu, pushing the joystick to the right will select the sub
menu and the digital display will scroll the following:
..Set Latching Relay 1… 20.9%
This is the menu at which to adjust the first level alarm relay state on the
Air Check O2 Monitor.
To change this value, push the joystick right to display the relay state. The
display will Indicate LATCH. Pushing the joystick down will change the relay
state from LATCHING to NON-LATCHING. Press ENTER to accept the value.
LATCHING 20.9%
NONLATCH 20.9%
After entering the relay state, the display will default back to the Set
Latching menu. The display will scroll the following:
..Set Latching…. 20.9%
From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following:
..Set Latching Relay 1… 20.9%
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Push the joystick down to select the next relay to be adjusted. The display
will scroll the following, Set Latching Relay 2.
..Set Latching Relay 2… 20.9%
This is the menu at which to adjust the second level alarm relay state on the
Air Check O2 Monitor. To change this value, push the joystick right to display
the relay state. The display will Indicate LATCHING. Pushing the joystick down
will change the relay state from LATCHING to NONLATCH. Press ENTER to accept
the value.
LATCHING 20.9%
NONLATCH 20.9%
After entering the relay state, the display will default back to the Set
Latching menu. The display will scroll the following:
..Set Latching…. 20.9%
From this main menu, pushing the joystick to the right will select the sub
menu and the digital display will scroll the following:
..Set Latching Relay 1… 20.9%
Push the joystick twice to select the Audio Alarm relay to be adjusted. The
display will scroll; Set Latching Audio Alarm.
..Set Latching Audio Alarm… 20.9%
This is the menu at which to adjust the Audio alarm relay state on the Air
Check O2 Monitor.
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NOTE: The O2 system must have the audio alarm option module installed to
access this menu. If this option is installed the display will indicate N/A,
(not available)
To change this value, push the joystick right to display the relay state. The
display will Indicate LATCHING. Pushing the joystick down will change the
relay state from LATCHING to NONLATCH. Press ENTER to accept the value.
LATCH 20.9%
NONLATCH 20.9%
After entering the fault relay state, the display will default back to the Set
Latching menu. The display will indicate the following:
..Set Latching…. 20.9%
5.5.5 Resetting a Latching Alarm
To reset a latching alarm relay, you must enter the password correctly and
then push the joystick down to enter the reset command. The Oxygen monitor
also has an internal 2-pin terminal block for connecting a remote reset
switch. (See Alarm Relay board, section 1.2.7)
5.5.6 Set Alarm Delay
Push the joystick down to access the next main menu, Alarm Delay. The display
will scroll the following:
…Alarm Delay… 20.9%
This is the amount of time an alarm level concentration of oxygen must be
present before the instrument’s gas concentration alarm(s) will be activated.
This menu will permit setting a user selected time delay for activating alarm
relays 1 and 2. You can select from 0 seconds up to 255 seconds after an alarm
level has been exceeded before the alarm relays to activate.
To change this value, push the joystick right to display the time screen. The
display will indicate a value between 0 and 255 seconds. Pushing the joystick
up increases the value and pushing the joystick down decreases the value.
Press ENTER to accept the value.
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005 20.9%
After entering the alarm delay, the display will default back to the Alarm
Delay menu and the display will scroll the following:
…Alarm Delay… 20.9%
NOTE: The alarm delay is only available for alarms 1 and 2. There is no delay
for the fault relay. Any system fault will immediately activate the Fault
Relay.
5.5.7 Set Zero Suppression
This function not used on the Oxygen monitor. It is only used to decrease the
sensitivity of selected gas sensors. Although the menu permits the changing of
settings, it is totally disabled in the Oxygen monitor. The factory default is
set at 000.
NOTE: This function is not available on the Air Check Oxygen monitor.
…Zero Suppression… 000
5.5.8 Set Alarm Thresholds
..Set Alarm Thresholds.. 20.9%
This main menu will permit adjusting the oxygen concentration percentage that
will activate alarm levels 1 and 2. If the Audio alarm output module is
installed, it will also permit setting the level at which the audio alarm will
activate.
NOTE: To activate the audio alarm, the AirCheck O2 monitor must have the audio
alarm option.
From this main menu, pushing the joystick to the right will select the first
sub menu and the digital display will scroll the following: Set Relay 1 Alarm
Threshold.
..Set Relay 1 Alarm Threshold… 20.9%
This is the gas concentration at which the instrument’s first level alarm will
be activated. To change the displayed value, push the joystick to the right to
display the first level alarm setting. The display will indicate a value
between 00.0% and 25.5%.
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Pushing the joystick up increases the value and pushing the joystick down
decreases the value. Press ENTER to accept the value.
19.5% 20.9%
After entering the relay state, the display will default back to the Set Relay
1 Alarm Threshold Menu. The display will scroll the following:
..Set Relay 1 Alarm Threshold… 20.9%
Push the joystick down to access the next sub menu; Set Relay 2 Alarm
Threshold, will scroll on the digital display.
..Set Relay 2 Alarm Threshold… 20.9%
This is the gas concentration at which the instrument’s second level alarm
will be activated. To change the displayed value, push the joystick to the
right to display the second level alarm setting. The display will indicate a
value between 00.0% and 25.5%.
Pushing the joystick up increases the value and pushing the joystick down
decreases the value. Press ENTER to accept the value.
18.0% 20.9%
After entering the relay state, the display will default back to the Set Relay
2 Alarm Threshold Menu. The display will scroll the following:
..Set Relay 2 Alarm Threshold… 20.9%
Push the joystick down to access the next sub menu; Set Audio Alarm Threshold, will scroll on the digital display.
..Set Audio Alarm Threshold… 20.9%
This is the gas concentration at which the instrument’s audio alarm will be activated. To change the displayed value, push the joystick to the right to display the second level alarm setting. The display will indicate a value between 00.0% and 25.5%.
19.5% 20.9%
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Pushing the joystick up increases the value and pushing the joystick down
decreases the value. Press ENTER to accept the value.
NOTE: The O2 system must have the audio alarm option module installed to
access this menu. If this option is installed the display will indicate N/A,
(not available)
NOTE: The audio can be set into only one alarm level. You can choose between
alarm level 1 or alarm level 2 or set a completely different setting.
After entering the relay state, the display will default back to the Set Audio
Threshold. Menu. The display will scroll the following:
..Set Audio Alarm Threshold… 20.9%
5.5.9 Set Alarm Hysteresis
PureAire’s oxygen monitor may be used as a control system. When used to
regulate oxygen levels the need of a dead band, “hysterisis” may be required.
This menu will permit the setting of the alarm hysterisis to a desired
concentration of Oxygen. When using hysteresis, the alarm set point now
becomes an average alarm setting for an action to occur. When adding the
hysterisis value to the alarm set point, this then defines the alarm and dead
band for an action to occur.
For example, if you require a valve to close at 14.9% oxygen level and to
reopen again at 15.5% oxygen level, you will set the Alarm Threshold at 15.2%
and set the hystersis value at 0.3%.
Average Alarm set point = 15.2% – Hysterisis 0.3% = 14.9%, Valve Off Average
Alarm set point = 15.2% + Hysterisis 0.3% = 15.5%, Valve On
To access this menu, push the joystick down to display the Set Alarm
Hysteresis menu. This will scroll on the digital display.
..Set Alarm Hysteresis… 20.9%
Push the joystick right to access the Set Alarm 1 Hyserisis. Pushing the joystick again to the right will display a value 0.0%, (factory default). Pushing the joystick up increases the percentage up to a maximum value of 2.5%. Adjust the digital display until the desired hysterisis value is selected.
0.3% 20.9%
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Press ENTER to accept this value. The digital display will revert back to Set
Alarm 1 Hysteresis.
..Set Alarm 1 Hysteresis… 20.9%
Push the joystick down to access the next sub menu; Set Alarm 2 Hysterisis
will scroll on the digital display. Pushing the joystick again to the right
will display a value 0.0%. Pushing the joystick up increases the percentage up
to a maximum value of 2.5%. Adjust the digital display until the desired
hysterisis value is selected.
..Set Alarm 2 Hysteresis… 20.9%
Press ENTER to accept this value. The digital display will revert to Set Alarm
2 Hysterisis.
..Set Alarm 2 Hysteresis… 20.9%
Push the joystick down to access the next sub menu; Set Alarm Audio Hysterisis
will scroll on the digital display. Pushing the joystick again to the right
will display a value 0.0%. Pushing the joystick up increases the percentage up
to a maximum value of 2.5%. Adjust the digital display until the desired
hysterisis value is selected.
..Set Audio Alarm Hysteresis… 20.9%
5.5.10 Set Sensor Adjust
This menu will permit fine-tuning of the oxygen readout to a known
concentration of Oxygen. It is recommended to adjust the oxygen display to
ambient oxygen levels of 20.9%. To access this menu, push the joystick down to
display the Sensor Adjustment menu. This will scroll on the digital display.
NOTE: It is recommended to warm up the Air Check Oxygen monitor for two hours
before making any adjustments to the sensor.
..Sensor Adjustment… 20.9%
Push the joystick right to access the first sub menu; Set Sensor Span will
scroll on the display. This is the menu that will permit fine adjustment of
the ambient oxygen reading to 20.9%.
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..Set Sensor Span.. 20.9%
Push the joystick right to access the sensor span. The display will indicate a
value between 0 and 255 counts. Pushing the joystick up increases the counts
and decreases the percent oxygen value displayed on the Air Check. Pushing the
joystick down decreases the counts and increases the oxygen value displayed on
the Air Check. As the counts increase and decrease the percent oxygen
displayed will also increase and decrease. Adjust the digital display until
20.9% + / – 0.1% is displayed. The actual oxygen reading will fluctuate from
20.8% to 21.0%.
093 20.9%
Press ENTER to accept this value. The digital display will revert to Set
Sensor Span.
..Set Sensor Span.. 20.9%
..Sensor Adjustment.. 20.9%
Press the joystick to the left to revert to the Sensor Adjustment menu.
NOTE: The “Set Module Zero” menu is not available for the Oxygen monitor This
menu was designed for PureAire toxic and corrosive gas monitors. When
selected, nothing will happen. Push the joystick Left to leave this menu.
5.5.11 Main Operation Mode
To select the main menu from any sub menu, push the joystick left until the
Main Menu appears. The digital display will indicate the following:
Oxygen 20.9%
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6: Maintenance & Sensor Verification
Only qualified personnel should perform maintenance and sensor verification
6.1 Sensor Verification
The earth is a stable source of calibrated oxygen at 20.9%, therefore under
ambient conditions you can perform a visual verification of the Air Check O2
monitor to verify its reading at 20.9%. As the oxygen sensor ages over time,
it may require a slight adjustment to 20.9%. The O2 monitor only requires
periodic testing with nitrogen to verify the cells response to 0% oxygen.
levels and, if needed, a slight annual adjustment of the sensor span to 20.9%.
6.1.1 Sensor Verification Gas
For testing the Air Check O2 monitor, PureAire recommends the use of nitrogen.
This can be purchased from your gas supplier or from the gas supplier listed
below.
6.1.2 Sensor Verification Equipment
For exposing the monitor to a known span gas, use the following. The gas and
regulator are available by separate order directly from your gas supplier.
This can be purchased from your gas supplier or from the gas supplier listed
below.
Part Number Description
CZF6D400281 Nitrogen 103 liter cylinder, 99.99% *
18102509
Regulator, On Demand **
CZF6D040283 Zero Grade Air 103 liter cylinder *
Quantity 1 1 1
*Air Liquide can be reached at 800-638-1197 **Industrial Scientific can be reached at 800-338-3287
NOTE: If the instrument is connected to a controller, set the controller to
the standby mode to avoid accidental alarms.
NOTE: If your safety protocol requires, you may subject the Air Check monitor
to different concentrations of oxygen span gas.
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6.2 Sensor Verification Procedure
CAUTION: Be sure to observe all safety guidelines when generating and using
nitrogen.
Under ambient non-oxygen deficient environments, Air Check O2 monitor will
indicate a display reading of 20.9%. As the sensor ages, the reading may
decrease in value. The following procedure should be used to adjust the
reading to 20.9%. It is recommended to verify and adjust the sensor span to
ambient 20.9% annually.
- Ensure that the Air Check O2 monitor is in a clean non-oxygen deficient environment.
- Enter the password. Refer to Section 5.3
- Select the Sensor Adjustment menu.
This menu will permit fine-tuning of the oxygen readout to a known concentration of Oxygen. It is recommended to adjust the oxygen display to ambient oxygen levels of 20.9%. To access this menu, push the joystick down to display the Sensor Adjustment menu. This will scroll on the digital display.
NOTE: It is recommended to warm up the Air Check Oxygen monitor For one hour before making any adjustments to the sensor.
..Sensor Adjustment… 20.9%
Push the joystick right to access the first sub menu; Set Sensor Span will scroll on the display. This is the menu that will permit fine adjustment of the ambient oxygen reading to 20.9%.
Push the joystick right to access the first sub menu; Set Sensor Span will scroll on the display. This is the menu that will permit fine adjustment of the ambient oxygen reading to 20.9%.
..Set Sensor Span.. 20.9%
Push the joystick right to access the sensor span. The display will indicate a value between 0 and 255 counts. Pushing the joystick up increases the counts and decreases the percent oxygen value displayed on the Air Check. Pushing the joystick down decreases the counts and increases the oxygen value displayed on the Air Check. As the counts increase and decrease the percent oxygen displayed will also increase and decrease. Adjust the digital display until 20.9% + / – 0.2% is displayed.
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093 20.9%
Press ENTER to accept this value. The digital display will revert to Set
Sensor Span.
..Set Sensor Span.. 20.9%
Press the joystick to the left to revert to the Sensor Adjustment menu.
…Sensor adjustment.. 20.9%
6.2.1 Sensor Verification to Nitrogen
PureAire recommends challenging the O2 monitor with nitrogen every 6 to 12
months. The monitor’s water filter has a ¼” male tube fitting designed for
connecting sample tubing from a Nitrogen cylinder. Expose the O2 cell to N2
using the On-Demand regulator. The reading will drop off to 1% or below in
less than one minute when the O2 sensor is exposed to pure N2. The system will
recover to 20.9% when the nitrogen is removed.
NOTE: For an accurate reading, please remove the water filter from the monitor
before connecting the gas cylinder.
OR If it is not possible to remove the water filter, please cover the drain
port on the water filter during this procedure. The span gas cylinder must be
connected directly to the monitor as shown in the following photo on pg. 45.
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6.2.2 Sensor Verification to a known concentration of Oxygen When testing the
O2 monitor to a known concentration of oxygen, the sensor inlet has as a ¼”
compression tube fitting designed for connecting the sample tubing. You can
connect ¼” OD sample tubing from a cylinder filled with Zero Grade air
directly to the tube inlet and expose the O2 cell directly. The On-Demand
Regulator will permit gas to flow at the flow rate programmed into the Sample
Draw Monitor. Expose the monitor for 1 minute and then adjust the reading to
20.9% when using Zero Grade air. Remove the tube from the On-Demand Regulator
and remove the Zero grade air from the monitor. The final reading should be
within ± 0.3% of the span gas concentration.
NOTE: To see a true zero, the entire Air Check O2 monitor needs be completely
immersed into a zero-oxygen environment.
O2 monitor Connected to gas cylinder
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7.0 Appendix
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How to convert 4-20mA current output to a 1-5 VDC voltage output
PureAire O2 Monitor 4-20mA output
User PLC input
Attach 250-ohm resistor to the PLC or device input
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