PureAire 99020 Air Check Ex O2 Deficiency Monitor Instruction Manual

June 16, 2024
PureAire

PureAire 99020 Air Check Ex O2 Deficiency Monitor

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
image

Product Information

Air Check Ex O2 Deficiency Monitor

Specifications:

Welcome to PureAire Monitoring Systems! Thank you for choosing our continuous life safety and process control toxic gas monitoring systems. We are dedicated to providing innovative solutions for our customers’ safety and environmental needs. Our products range from small systems to total multi-point turnkey computerized packages. With our proprietary sensor cell technology and state- of-the-art electronics, we can interface with the latest distributive or PLC based control systems. You can trust our experience, commitment to service, and innovative products to meet your specific monitoring requirements now and in the future.

Thank you once again for investing in PureAire Monitoring Systems. We are proud to have you as a valued customer.

Sincerely,

Albert A. Carrino

President

Product Usage Instructions

Installation:

  1. Before assembling the electronics into the housing, ensure that all sample tubing is not restricted or pinched.
  2. Make all wiring terminations to the monitor and reassemble the electronics inside the enclosure before powering the monitor. Avoid shorting any wiring to the metal enclosure to prevent blowing the internal fuse and voiding the warranty.
  3. For further installation instructions, refer to the Instruction Manual.

Air Check Oxygen Monitor Guidelines:

The following actions may damage the Air Check Oxygen monitor, so please avoid them:

  1. Do not connect the monitor to any voltage that exceeds 24 Volts DC or any AC Voltage. The monitor requires 24 VDC regulated power.
  2. Do not power the Air Check Oxygen monitor with the oxygen sensor unplugged from the main PC board. Also, avoid connecting the O2 sensor to the PC board while the monitor is powered, as it can cause damage to the O2 sensor.
  3. Never exchange the electronics with an oxygen sensor from a different monitor as the oxygen sensor cell is matched to the electronics.
  4. During calibration or challenging of the Air Check O2 Ex monitors:
    • b. When testing Sample Draw and Ex type monitors, use an On Demand regulator to expose the span gas to the monitor.
    • c. Expose the monitor to span gas blends consisting of Oxygen and Nitrogen only. Do not expose the monitor to any combustible gas such as Methane or Hydrogen, as it can damage the oxygen zirconium sensor cell.
  5. Avoid exposing the Oxygen monitor to silicone, Freon, or corrosive compounds as they can cause a loss of sensitivity and damage the sensor.
  6. Do not expose the monitor to high flow air or install it directly in front of fans. High airflow can cool the oxygen sensor and result in inaccurate readings.
  7. When using the Air Check O2 monitor, do not expose the oxygen sensor directly to a water stream. In areas requiring wash downs, cover and protect the monitor and power supply. Contact PureAire for details on a waterproof enclosure.

Frequently Asked Questions

Q: What power supply does the Air Check O2 monitor require?

A: The Air Check O2 monitor requires 24 VDC regulated power. Do not connect the monitor to any voltage that exceeds 24 Volts DC or any AC Voltage.

Q: Can I power the Air Check Oxygen monitor without the oxygen sensor plugged in?

A: No, do not power the Air Check Oxygen monitor with the oxygen sensor unplugged from the main PC board. It can cause damage to the O2 sensor. Ensure the O2 sensor is connected to the PC board before powering the monitor.

Q: Can I use a different oxygen sensor from another monitor with the Air Check O2 monitor?

A: No, never exchange the electronics with an oxygen sensor from a different monitor. The oxygen sensor cell is matched to the electronics.

Q: What gases should I use for calibrating or challenging the Air Check O2 Ex monitors?

A: When calibrating or challenging Sample Draw and Ex type monitors, use an On Demand regulator to expose the span gas to the monitor. Expose the monitor to span gas blends consisting of Oxygen and Nitrogen only. Do not expose the monitor to any combustible gas, such as Methane or Hydrogen, as it can damage the oxygen zirconium sensor cell.

Q: Can I expose the Oxygen monitor to silicone, Freon, or corrosive compounds?

A: No, avoid exposing the Oxygen monitor to silicone, Freon, or corrosive compounds as they can cause a loss of sensitivity and damage the sensor.

Q: Can I install the Air Check O2 monitor in an area with high airflow or directly in front of fans?

A: No, do not expose the monitor to high flow air or install it directly in front of fans. High airflow can cool the oxygen sensor and result in inaccurate readings.

Q: Can I expose the oxygen sensor directly to a water stream during operation?

A: No, when using the Air Check O2 monitor, do not expose the oxygen sensor directly to a water stream. In areas requiring wash downs, cover and protect the monitor and power supply. Contact PureAire for details on a waterproof enclosure.

Welcome to PureAire Monitoring Systems

I would 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 can provide 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 am proud to welcome you to our family of valued and satisfied customers.
Sincerely,

Albert A. Carrino President

When assembling the electronics into the housing please ensure that all sample tubing is not restricted or pinched PureAire-99020-Air-Check-Ex-O2
-Deficiency-Monitor-fig1Please make all wiring terminations to the monitor and reassemble the electronics inside the enclosure before powering the monitor.
Shorting any wiring to the metal enclosure will blow the internal fuse and void your warranty.
Please read the Instruction Manual for more information

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 calibrating or challenging the Air check O2 Ex monitors,

    • a. Do not expose the monitor to flow rates that exceed ½ liter per minute, (500 cc per minute) flow.
    • b. When testing Sample Draw and Ex type monitors use an On Demand regulator to expose the span gas to the monitor.
    • c. 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.
  5. Do not expose the Oxygen monitor to silicone, Freon, or corrosive compounds. They can cause a loss of sensitivity and damage the sensor.

  6. Do not expose the monitor to high flow air or install it directly in front of fans. The high air flow can cool the oxygen sensor and cause an inaccurate reading.

  7. When using the Air Check O2 monitor, Do not expose the oxygen sensor directly to a water stream. In areas requiring wash downs, cover and protect the monitor and power supply. Contact PureAire for details on a waterproof enclosure.

  8. The Factory Password for entering the menus is 557

Introduction

The Air Check O2 Ex series monitoring system is a self-contained sample draw Oxygen deficiency detection system suitable for Class 1, Div. 1 & 2, Groups B, C, D, Zones 1 & 2, Groups IIB+H2, IIA hazardous environments. It is a compact gas monitoring system that is 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.
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 confined spaces or areas where inert gases are used, the Air Check O2 Deficiency Monitor does not drift or loose sensitivity when the weather or temperature changes. The electronics are housed in an explosion proof housing designed for installation in Class 1, Div. 1 & 2, Groups B, C, D, Zones 1 & 2, Groups IIB+H2, IIA hazardous environments.
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 O2 deficiency monitor.

Key Features

The Air Check O2 Ex monitor incorporates several user-friendly features designed to simplify installation, operation, and maintenance.

Long Life Zirconium Oxide O2 Sensor
The system’s O2 sensor cell has a life of well over 10 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 Ex monitor can detect low oxygen levels in confined spaces and process tools without the need of a reference gas.

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.

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.

Component Identification

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-fig3

  1. Front Cover — This is a removable, waterproof cover that protects the interior of the transmitter. It threads onto the metal transmitter housing.
  2. Digital Display — This displays the Oxygen levels in percentage. The normal oxygen level on earth is 20.9%
  3. Sample Inlet — This inlet permits the flow of oxygen to enter the sensor cell.
  4. Sample Exhaust — This permits the flow of oxygen to exit the enclosure.
  5. Seal fitting — This is the sealed opening in the transmitter housing for connecting the 4-20 mA output and 24 VDC wiring.
  6. Transmitter Mounting Tabs — Mounting holes are provided on both sides of the transmitter housing to permit convenient wall mounting.
  7. Alarm Indicators — 3 multicolored LED indicators for showing:
    • Alarm level 1 Orange
    • Alarm level 2 Red
    • Fault Alarm Yellow
  8. Joystick — Used for selecting and adjusting the built-in menus. The Air Check O2 monitor is available with optional dual level user selectable
  9. Front Panel Cover Screws — These captive screws are used to mount the display front panel and O2 electronics to the enclosure.
  10. 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
  11. Oxygen Sensor chamber — Used to mount the zirconium O2 sensor cell

Front View with front cover removed

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-fig4 O2 monitor with front cover removed

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
fig5

Transmitter Interior

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-fig6

  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.

Alarm Relay Board

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-fig7

Specifications

NOTE: For our continual product improvement, all specifications are subject to change without notice.

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 134°F (-40° to +55°C); consult PureAire for lower or higher operating temperatures.
  • Humidity: 0 to 95% RH; consult PureAire for sensors which can operate in 100% condensing RH environments.

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 3-digit backlit LCD display joystick operated menus

Signal Outputs

  • Local Display: Digital display calibrated for Oxygen. The range is stated on the model label and can also 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 scrolling and display the gas again.
  • Standard Analog Output: DC 4-20 mA
  • Relay Output: Dual level user selectable alarm relays and one fault relay Rated, 2amps @ ≤ 24VAC or 24VDC

Electrical Requirements

  • Power: 24 VDC external power. A regulated 24VDC power supply is required.
  • Consumption: Approximately 300mA

Physical Characteristics

  • Dimensions: 6.625 (W) x 5.50 (H) x 5.25 (D) inches; 168 x 140 x 134 mm
  • Weight: 12 pounds (5.5 kg)
  • Enclosure Type: Explosion proof designed for installation in Class I, Div. 1 & 2, Groups B C and D, Zones 1 & 2, Groups IIB+H2, IIA hazardous areas.

AirCheck O2 System Default Factory settings

The Air Check O2 Deficiency Monitor, when supplied with the optional Relay module, is shipped with factory defaults for the alarm relay settings. The following are the factory defaults:

Menu Function Factory Default Menu Defined
Set 4-20mA loop The mA output is set at the factory using a calibrated
Fluke meter. Use this function to adjust the Oxygen monitors 4mA, (Zero) and

20mA, (Span) to your PLC or distributive control system.
Set Formats

LED and alarm relay State **

| Alarm 1 = Normal Alarm 2 = Normal Fault = Normal| Do you want the relays to energize, (normal) or de-energize, (inverted) when the alarm activates?
Set Alarm Threshold Polarity| Alarm 1 = Inverted Alarm 2 = Inverted Audio = Inverted*| Do you want to alarm at a level higher, (normal) or lower, (inverted) than the alarm threshold?
Set Latching| Alarm 1 = Non-latching Alarm 2 = Non-latching Audio = Non- latching| Do you want the alarm to automatically reset? (non-latching) or do you want to manually reset the alarm? (latching)
Alarm Delay| Alarm = 5 seconds| How long do you want to wait until the alarms activate?
Zero Suppression| 000 = 0.00%| This function is Not Enabled on the Oxygen monitor.
Set Alarm Thresholds| Alarm 1 = 19.5 %

Alarm 2 = 18.0 % Audio = 19.5%*

| At what level do you want to alarm?
Set Alarm Hysteresis| Alarm 1 = 0.0 %

Alarm 2 = 0.0 % Audio = 0.0 %

| For use when using the O2 monitor for control or valves and process.

See Section 5.5.9

Sensor Adjustment| No factory default| For use when dynamically gas calibrating the Oxygen monitor to a known span gas.

See Section 6.2

Manage Passwords| Factory default is 557| 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 5.5.2
  • NOTE: The Audio alarm feature is optional.
  • NOTE: The LED indicators on the front panel are connected directly to the alarm relays.

Installation

Site Requirements

The Air Check O2 Ex monitor enclosure should be mounted in an area free of vibration and electrical noise or interference. If possible, avoid areas with high temperatures or condensing humidity.
NOTE: The Air Check O2 Ex monitor is designed for installation in Class 1, Div. 1 & 2, Groups B, C, D, Zones 1 & 2, Groups IIB+H2, IIA hazardous environments.

Mounting

Transmitter Enclosure

The Air Check O2 Ex monitor is designed primarily for wall mounting and should be installed at a height convenient for operation, maintenance, and viewing of the instrument display.

Air Check O2 Ex 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 flame Arrestors, seal fitting and inlet dust filter. PureAire-99020-Air-
Check-Ex-O2-Deficiency-Monitor-fig8

Air Check Sample Inlet Filter

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-fig9

The Air Check Ex monitor is a sample draw type. The internal sample pump flow rate 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 the sample line is blocked, the fault indicator will illuminate and the pump will accelerate to try and re establish the proper flow rate. If the line is cleared, the pump will speed will slow down and the fault light will turn off when the flow rate is back to factory setting.
  • 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.

To protect the pump and flame arrestor from dust, the use of a particulate filter is supplied.  On installation, attach the particulate filter to the inlet using the tygon sample tubing supplied.  Ensure the correct flow by aligning the arrow towards the flame arrestor.

Depending on the environment, replacement of this filter should be performed every 6 to 12 months.  In dusty environments, filter replacement may need to be replaced more frequently.  If the filter becomes completely blocked, the internal flow sensor will detect the loss of flow and activate the fault relay and LED.  Order filter part number 90115

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: PureAire-99020-Air-Check-Ex-O2
-Deficiency-Monitor-fig10PureAire 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.

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-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. PureAire Monitoring Systems, Inc.

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 between 0.10 and 0.25 liters per minute

Normal Operation

The Air Check O2 monitor is a single point monitor designed for the continuous detection and measurement of ambient oxygen concentration levels.

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.
CAUTION: DO NOT connect to a powered current loop receiver. The Air Check Oxygen monitor supplies the current loop power.

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 Analog Signal
**Supply Voltage Out of Range Fault code 16 Analog output drops to 2 mA
Transmitter cable cut Analog output drops to 0 mA

O2 Cell complete failure

Fault Code 128

| 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
EEPROM Fault 08| Analog output drops to 2mA

NOTE: All system faults are displayed on the front panel. Each fault has its 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.

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)

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 Check for power and proper operation
Condition / status when operating properly Unit should be outputting a 17.4

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.

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.

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.

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 is required. Resetting the alarms can be performed through use of the joystick or through the use of the remote reset function.
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.

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 on line while making any changes to the menus.

Joystick Operation

The Air Check O2 monitor uses a 4-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 – 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

Program Flowchart

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
fig13 NOTE: All numerical values shown are only examples and are not Factory DefaultsPureAire-99020-Air-Check-Ex-O2
-Deficiency-Monitor-fig14 NOTE: All numerical values shown are only examples and are not Factory DefaultsPureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
fig15

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.
  2. Push the joystick again once more to the right to enter the input screen. The letter A will appear and flash. NOTE: The display has characters that start with A through Z and 0 through 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.
  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.
  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.
  6. Push the joystick in the center to enter the password. If you entered it correctly the display will scroll Password OK. 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.

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.
  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
  3. Push the joystick to the right to enter the input screen. The letter A will appear and flash. 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.
  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.
  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.
  7. Push the joystick in the center to enter the password. This will display the next command, Re-Enter New Password
  8. Push the joystick to the right to enter the input screen. The letter A will appear and flash.
  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.
  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.
  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.
  12. Push the joystick in the center to enter the password. If you entered it correctly the display will scroll “New Password Entry OK”. 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 lose 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.

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 Push the joystick right to display the status. If enabled it will display ”Enabled” 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” Reset User Password
This menu permits you to reset the password back to 557, as set at the factory.

Push the joystick right to display the menu, “Reset to factory Default”. 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 p lease contact PureAire with your s erial number or DTM number

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.

Set 4-20mA loop 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 volt meter 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: 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. Push the joystick to the left brings you back to the pervious Main menu. The digital display will scroll the following: Push the joystick down to access the next sub menu; Set 20mA Span will scroll. 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. Push the joystick to the left brings you back to the pervious Main menu. The digital display will scroll the following: Push the joystick down to access the next sub-menu; Force loop will scroll. NOTE: The Force Loop function is not available on the Air Check O2 monit It was designed for toxic and corrosive gases.
This is the sub menu is only used on PureAire’s toxic and corrosive monitors. Push the joystick to the left brings you back to the pervious menu. The digital display Will scroll the following: NOTE: When adjusting the 4 mA and 20mA settings, the actual reading may quickly switch from your setting and an alternate number. This is a run-time indication and is normal.

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: 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: 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. After entering the relay state, the display will default back to the Set Formats menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick down to access the next main menu, Set Formats. The display will scroll the following: 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. After entering the relay state, the display will default back to the Set Formats menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick twice to select the fault relay to be adjusted. The display will scroll: Format Fault Relay. 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. After entering the relay state, the display will default back to the Set Formats menu. The display will scroll the following: 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. 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. 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. After entering the relay state, the display will default back to the Set Alarm 1 Polarity menu. The display will scroll the following: 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. 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. After entering the relay state, the display will default back to the Set Relay 2 Alarm Threshold menu. The display will scroll the following: 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. 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 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.

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. After entering the relay state, the display will default back to the Set Audio Alarm Polarity menu. The display will scroll the following:

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.

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) 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: 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. After entering the relay state, the display will default back to the Set Latching menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick down to select the next relay to be adjusted. The display will scroll the following, Set Latching Relay 2. 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. After entering the relay state, the display will default back to the Set Latching menu. The display will scroll the following: From this main menu, pushing the joystick to the right will select the sub menu and the digital display will scroll the following: Push the joystick twice to select the Audio Alarm relay to be adjusted. The display will scroll; Set Latching Audio Alarm. This is the menu at which to adjust the Audio alarm relay state on the Air Check O2 Monitor.
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. After entering the fault relay state, the display will default back to the Set Latching menu. The display will indicate the following:

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)

Set Alarm Delay

Push the joystick down to access the next main menu, Alarm Delay. The display will scroll the following: 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. After entering the alarm delay, the display will default back to the Alarm Delay menu and the display will scroll the following: 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.

Set Zero Suppression
This function is 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.

Set Alarm Thresholds

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 Air Check 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. 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%.
Pushing the joystick up increases the value and pushing the joystick down decreases the value. Press ENTER to accept the value. After entering the relay state, the display will default back to the Set Relay 1 Alarm Threshold Menu. The display will scroll the following: Push the joystick down to access the next sub menu; Set Relay 2 Alarm Threshold, will scroll on the digital display. 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. After entering the relay state, the display will default back to the Set Relay 2 Alarm Threshold Menu. The display will scroll the following: Push the joystick down to access the next sub menu; Set Audio Alarm Threshold, will scroll on the digital display. 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%.
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 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, “hysteresis” may be required for the alarm relays. This menu will permit the setting of the alarm hysteresis 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 hysteresis 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 hysteresis value at 0.3%.

Average Alarm set point = 15.2% – Hysteresis 0.3% = 14.9%, Valve Off
Average Alarm set point = 15.2% + Hysteresis 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. Push the joystick right to access the Set Alarm 1 Hysteresis. 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 hysteresis value is selected. Press ENTER to accept this value. The digital display will revert back to Set Alarm 1 Hysteresis. Push the joystick down to access the next sub menu; Set Alarm 2 Hysteresis 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 hysteresis value is selected. Press ENTER to accept this value. The digital display will revert back to Set Alarm 2 Hysteresis. Push the joystick down to access the next sub menu; Set Alarm Audio Hysteresis 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 hysteresis value is selected.

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. 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 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%. Press ENTER to accept this value. The digital display will revert back to Set Sensor Span.

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.

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:

Maintenance & Sensor Verification

Only qualified personnel should perform maintenance and sensor verification

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%.

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.

Sensor Verification Equipment

This can be purchased from your gas supplier or from the gas supplier listed below.

Part Number Description Quantity
CZF6D400281 N2 99.99% balance air * 1
1810259 Demand Flow Regulator ** 1
CZF6D040283 Zero Grade Air 103 liter cylinder * 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 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.

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.

  1. Ensure that the Air Check O2 monitor is in a clean non-oxygen deficient environment. (It is also permissible to challenge the monitor to a cylinder of zero air if the monitor is in an oxygen deficient environment)
  2. Enter the password. Refer to Section 5.3
  3. Select the Sensor Adjust 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 two hours before making any adjustments to the sensor.

  • 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%.
  • 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.
  • Press ENTER to accept this value. The digital display will revert back to Set Sensor Span.
  • Press the joystick to the left to revert back to the Sensor Adjustment menu.

Sensor Verification to Nitrogen

PureAire recommends challenging the O2 monitor with nitrogen every 6 to 12 months. The sensor inlet has a ¼” compression tube fitting designed for connecting the dust filter. You can connect ¼” OD sample tubing from a Nitrogen cylinder directly to the dust filter.  Expose the O2 cell directly to the nitrogen cylinder at a flow rate of 500 cc/min. 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.

Sensor Verification to a known concentration of Oxygen

When testing the O2 monitor to a known concentration of oxygen, the sensor inlet has 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 sample tube inlet and expose the O2 cell directly using the On Demand Regulator. Expose the monitor for 1 minute and then adjust the reading to 20.9% when using Zero Grade air. Disconnect the 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

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
fig116

Appendix

CONTACTOR/FAN CONNECTION

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
fig117

  • OK TO USE EXTERNAL SUPPLY AS LONG AS VOLTAGE IS 24VDC/AC OR LESS.

NOTE: ENSURE CONTACTOR CHOSEN HAS CORRECT COIL VOLTAGE AND IS CURRENT- RATED FOR YOUR LOAD

How to convert 4-20mA current output to a 1-5 VDC voltage output

  • PureAire O2 Monitor 4-20mA output
  • User PLC input

PureAire-99020-Air-Check-Ex-O2-Deficiency-Monitor-
fig118

  • Attach 250-ohm resistor to the PLC or device input

Contact

PureAire Monitoring Systems, Inc.

Rev 4.13 May 2023

References

Read User Manual Online (PDF format)

Loading......

Download This Manual (PDF format)

Download this manual  >>

PureAire User Manuals

Related Manuals