Met One Instruments 9012-4 6 Channel Particle Counter Instruction Manual

Met One Instrument 9012-4 6 Channel Particle Counter

Product Information

Specifications

• Model: 83201 AQ PROFILER
• Manufacturer: Met One Instruments, Inc
• Address: 1600 NW Washington Blvd. Grants Pass, Oregon 97526
• Telephone: 541-471-7111
• Facsimile: 541-471-7116

Product Usage Instructions

1. Installation
   Ensure proper installation by following these steps:

   • Mounting: Securely mount the device as per the guidelines provided in the manual.
   • Connections/Wiring: Connect the device following the wiring instructions provided.
   • Default Settings: Verify and adjust default settings as needed for your application.

2. Description
   The product is equipped with a laser diode-based sensor that is classified as a Class I product. It is designed for accurate profiling of air quality parameters.

3. Serial Communication
   The device supports serial communication for data transfer and control. Refer to the manual for detailed instructions on setting up and utilizing serial communication.

Frequently Asked Questions (FAQ)

• Q: What should I do if I encounter difficulties with the product?
  A: If you experience any issues, refer to the printed documentation for troubleshooting steps. If problems persist, contact Technical Support during business hours for assistance.

• Q: Is the product safe to use?
  A: The product is designed for safe operation under normal conditions. Follow all safety guidelines provided in the manual to ensure safe usage.

Copyright Notice

83201 Operation Manual
© Copyright 2018 Met One Instruments, Inc. All Rights Reserved Worldwide. No part of this publication may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other language in any form by any means without the express written permission of Met One Instruments, Inc.

Technical Support
Should you require support, please consult your printed documentation to resolve your problem. If you are still experiencing difficulty, you may contact a Technical Service representative during normal business hours—7:30 a.m. to 4:00 p.m. Pacific Time, Monday through Friday.

• Voice: 541-471-7111
• Fax: 541-471-7116
• E-Mail: service@metone.com
• Mail: Technical Services Department Met One Instruments, Inc. 1600 Washington Boulevard Grants Pass, OR 97526.

Safety Notice

• The contents of this manual have been checked against the hardware and software described herein. Since deviations cannot be prevented entirely, we cannot guarantee full agreement. However, the data in this manual is reviewed regularly and any necessary corrections are included in subsequent editions.
• Faultless and safe operation of the product presupposes proper transportation, storage, and installation as well as careful operation and maintenance. The seller of this equipment cannot foresee all possible modes of operation in which the user may attempt to utilize this instrumentation.
• The user assumes all liability associated with the use of this instrumentation. The seller further disclaims any responsibility for consequential damages.

NOTICE

• CAUTION Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.
• WARNING This product, when properly installed and operated, is considered a Class I laser product. Class I products are not considered to be hazardous.

This product incorporates a laser diode-based sensor that is a CLASS 1 product as defined in 21 CFR, Subchapter J, of the Health and Safety Act of 1968. This applies when the instrument is used under normal operating conditions and with proper maintenance. Service procedures performed on the sensor can result in exposure to invisible laser radiation. Only a factory-authorized person must perform service on this instrument. The laser diode-based sensor inside this instrument has a warning label on it as shown below.

INSTALLATION

Mounting
The AQ profiler module can be mounted using the eight slotted openings along the edge of the unit.

Connections/Wiring
Three terminal blocks for electrical connectors are located on one side of the AQ profiler. The pin-out detail for the electrical connections is clearly labelled at each wire input. Figure 1.2 shows all the connections for the AQ profiler assembly.

Table 1.2 Terminal Block Connection Descriptions

Default Settings
The AQ Profiler is shipped with the following default settings.

Communication:
9600 Baud Rate, 8 Data Bits, No Parity, 1 Stop Bit, No Flow Control.

• Sample Time: 60 seconds
• Sample Mode: Continuous
• Unit ID: 1
• Modbus Slave Address: 1

DESCRIPTION

AQ Particle Counter
The AQ particle counter can size and count airborne particles in up to eight size ranges. Particles are sized and then counted in one of the eight counters. Depending on the settings, data is transferred automatically at the end of a sample period or continuously to an external recording device. The AQ profiler has terminal communications protocols.

Sheath Air
When a particle counter is to be used to sample aerosols containing high concentrations of particles, the sensor should incorporate sheath air to prevent particles from contaminating the internal optics of the sensor. The particle-laden sample air is enclosed in a sheath of clean filtered air that prevents particles from escaping. The AQ particle counter is equipped for and requires sheath air for operation.

Detection
The particle counter uses scattered light to measure and count particles. Sample air is drawn into the detector chamber and subjected to an intense laser beam located at right angles to the flow. The laser beam has been shaped to produce a flat very thin beam producing a small sample area. Light travels through the sample stream and terminates in the light trap. Particles pass through the laser beam and scatter light. The amount of light scattered is proportional to the size of the particle. A portion of this light scatters toward the elliptical mirror. This light is then directed to the detector. The output of the detector is then analyzed to determine the number of particles and the size of the particles. Met One Instruments uses the elliptical mirror to maximize collected light without the need for complex focusing optics.

Sizing and Counting
The amount of scattered light is converted to a voltage pulse, and based on the amplitude of the pulse signal it will pass through one or more of the size discriminators and into the associated counter(s).

Calibration
Calibration is performed using ideal (PSL) spheres, which provide a powerful tool for assessing the sensitivity, accuracy, resolution and false count level. The particle detector is compared to a reference mono-dispersed (single size) suspension of polystyrene latex (PSL) spheres in clean filtered air for both calibration and certification of performance specifications. This calibration technique serves two purposes:

1. Provides a standard traceable reference.
2. Provides a measure of how well the unit maintains its calibration (reproducibility).

SERIAL COMMUNICATION

There are three modes of communication:

1. User communication – This is a user-interactive mode using simple letter commands for ease of use.
2. Computer communication – This mode is used for computer-to-device communication. It has a level of data integrity.
3. Legacy communications – This mode is for backward compatibility with the original 9722 and 212 instruments. This mode is deprecated and should only be used for compatibility with existing installations. All new installations should use the newer serial conventions.

Table 3.1 Command-List

bit flags for combinations needed

e.g. RO 11 = Flow, Temperature, RH

RQ| Request last reading.
RV| Get product information.
RZ| Get available Channel Size information.
SB| Get/Set serial baud rate. 3=2400, 4=4800, 5=9600, 6=19200,

7=38400,8=57600,9=115200.

SPR| RH Setpoint to turn inlet heater on.
ST| Get/Set Sample Time in Seconds.

User Communication

• In the user communication mode (terminal mode), press the Enter key, , three times to enter the mode. In this mode, simple character commands can be issued with no character required.
• An asterisk character appears during wake-up, and also after a command has been completed. The asterisk indicates that the instrument is ready for a new command. Commands are echoed back from the instrument in this mode.
• Commands are terminated by the Enter key .
• A help menu can be viewed by sending H, h, or ?; giving all the commands available to the user.
• Pressing , X or Q will exit user mode.

Computer Communication
In the computer communication mode, the command format has an optional level of data integrity – checksum. This mode is entered whenever a character is sent to the instrument. Character echo is suppressed in this mode.

Computer Command Format
The computer command has the following format:

*< Esc>Cmd p1 p2cs*
Computer commands are prefaced with an (0x1B) character followed directly by a command, Cmd, which is variable in length depending on the command. After the command characters, there can be zero or more parameter fields, p1 p2. Each parameter field is delimited by one or more Space characters (0x20). The end of the message is signalled by the Checksum Delimiter character (0x2A) followed by the checksum, cs, and finally terminated with a carriage return (0x0D) character. Note: the *cs is optional and should be used if data integrity enforcement is required for the application.

A computer command example follows:

• RV*00234
• All command responses are terminated with a checksum
• RV 092, 99999-1, R9.9.9*00234

Checksum Computation

• Checksum is calculated as the 16-bit unsigned integer sum of all of the characters after the character up to but not including the Checksum Delimiter Character * (0x2A). It is printed out as an ASCII decimal number.
• The result is always 5 characters in length with leading zeros.
• The checksum may be bypassed in the following manner: *//.

Legacy Communication
In the Legacy communication mode, the system emulates the serial protocol of the 9722 and 212 instruments. The PT (protocol type) command is used to set this mode when needed. Press the Enter key three times to enter Terminal Mode, much the same as User Mode above. The Legacy Mode prompt is the Greater Than symbol “>”. Commands are single characters and act immediately upon pressing the key. Those that require additional input will be terminated by the Enter key. A Help Menu is available by pressing the H or ? keys.

Table 3.3 Legacy Command-List

This mode is deprecated and should not be used for new installations. When Legacy Mode is enabled, the Terminal mode only supports the limited set of Legacy commands. The full set of commands is still available in Computer Mode only when Legacy Mode is turned on.

MAINTENANCE

Service Schedule

• WARNING: The AQ Profiler can only be serviced or calibrated by factory-authorized personnel. Unauthorized maintenance on the AQ Profiler may result in exposure to laser radiation that can cause blindness and void the warranty.
• Calibrating particle sensors like the one in the Model AQ Profiler requires specialized equipment and a skilled technician. Met One Instrument maintains a calibration facility for calibrating particle counters according to industry-accepted methods using NIST traceable standards. The AQ profiler should be calibrated yearly.

Table 4.1: Service

OPERATION

Powering the AQ Profiler
The AQ Profiler can operate from a voltage input of 10.5 to 15.5 volts. See 1.2 for the power connector pinout.

Communication
You can use a terminal program such as Hyper-Terminal to communicate with the profiler.

RS-232 and RS-485 Operation
Communication wires can be directly connected to the left-most terminal block of the profiler. See 1.2 for the connector pinout.

Sample Air Flow
You will be required to supply a vacuum to the outlet nozzle of the AQ Profiler for it to sample. You will also need to supply filtered air for the air sheath. For the air filter, we reco0.1-micron1-micron in-line filter (MOI#580294). We recommend this filter if a mass flow sensor is used as well. The filter should be installed upstream from the mass flow sensor to protect its delicate sensor from contamination generated by the pump. The flow rate is critical to the proper operation of the unit. The vacuum should be smooth, without pulsation. Since most pumps create a pulsation by their very nature a surge chamber and restriction should be employed to reduce the airflow to a steady stream. The calibration of the profiler was done at a 1.0 L/min inlet flow rate and an increase in flow rate will make particles appear smaller. Changes in pump voltage can cause a shift in flow rate as well. Selecting the type of vacuum pump will be of some importance. A diaphragm pump generally has a long life between maintenance but generates large pulsations and requires larger surge chambers to suppress them. Rotary vane pumps generate a higher frequency pulsation and can be filtered with a smaller chamber or a plenum. A coarse filter should be placed before the pump to keep contaminants from damaging the pump. This is especially critical with rotary vane pumps.

Flow System specifications
A 10V reference voltage connection is available for the use of a flow sensor that requires this reference. The +10V can only supply 10 mA of current. The flow signal input voltage is 0 to 5V max. Met One also offers a differential pressure flow sensor, part number 82258, which requires power from the +12V flow input due to the higher current demand of the DP sensor. Currently, only this Met One DP sensor is supported.

Pump specifications
DC limit for an external pump is 0.5A. An open collector pulse width modulated signal is used to control pump speed. It can be used to drive two or three- wire DC pumps. Units are configured for 3 wire pumps. Three wire pumps will run full-on when the control wire is open. When the control wire is grounded the pump shuts down. The pump speed is controlled with a 1 kHz PWM signal. A two-wire pump (typically a brush motor) can also be controlled by connecting to the +12V and the PWM1 line if the logic is reversed. Reversing the logic is done with a hardware jumper (JP2). The jumper JP2 is located on the underside of the terminal board.

RH and Inlet Heater
The RH (Relative Humidity) can affect the size of airborne particles when RH is greater than 50%. The particles swell in size due to moisture absorption and “seeding”. The use of an inlet heater can ‘dry’ out the particles and eliminate this source of error. The AQ Profiler can read an RH sensor and control a solid-state relay which switches the high current required for the heated inlet tube (MOI#9431). The set point for turning on the inlet tube heater is user-configurable. Generally, a set point of 40% is recommended. The RH sensor can be placed between the outlet nozzle and the vacuum pump. It is recommended to use an inlet heater with the RH sensor below the heater. Only HTR1 output is currently supported. If the unit will be used in low humidity conditions only then the inlet heater is not necessary and can be omitted.

AQ Flow (MOI #83170)

NOTE:
The flow system listed below is an option and is only provided if the customer specifically ordered it.

The AQ Flow system includes a flow sensor, temperature sensor and vacuum pump for connection to the AQ Profiler. Connections from the flow system to the profiler are shown below.

SPECIFICATIONS

source.
Threshold| 0.3 μm
Number of channels| 8 channels that can be user-defined. Each channel will measure the selected size and greater. Range: 0.3μm to 10μm
Concentration Range| 0-9,000,000 particles per cubic foot
Accuracy| ±10% to calibration aerosol
Sample Air Flow Rate| 1.0 LPM
Sheath Air Flow Rate| 1.0 LPM
Flow Control| PWM Pump driver
Communications| RS-485, half duplex RS-232
Connections| Terminal block connections on the side of the enclosure: DC power, RS-232, RS-485 sensor, RS-485 modem, Heater 1, Heater 2, Flow 1, Flow 2, Pump 1, Pump 2, RH sensor, AT sensor.
Operating Temperature| 0º to +50º C
Storage Temperature| -20º to +60º C
Power| 10.5-15.5 VDC. Average operating current 70mA, 600mA with AQ Flow, 1.3A with AQ Flow and heated inlet.
Size| Height: 3.63in, Width: 4.75in, Length: 2.34in
Weight| 1 lb 10 oz
Serial Settings| Baud = 9600, 8 data bits, no parity, and 1 stop bit. (factory Default) 115200, 57600, 38400, 19200, 9600, 4800, 2400 (selectable).
Communications Protocol| Terminal Command Set

Met One Instruments, Inc

• 1600 NW Washington Blvd. Grants Pass, Oregon 97526
• Telephone 541-471-7111
• Facsimile 541-471-7116

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