Analytical Industries GPR-1200 MS ATEX Portable PPB Oxygen Analyzer User Manual
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Oxygen, the fuel for this electrochemical transducer, reacts chemically at the sensing electrode to produce an
electrical current output proportional to the oxygen concentration in the gas phase. The sensor’s signal output is
linear over all four ranges and remains virtually constant over its useful life. The sensor requires no maintenance or
electrolyte addition and is easily and safely replaced at the end of its useful life.
The signal generated by the sensor is processed by state of the art low power micro-processor based digital
circuitry. The first stage amplifies the signal. The second stage eliminates the low frequency noise. The third stage
employs a high frequency filter and compensates for signal output variations caused by ambient temperature
changes. The result is a very stable signal. Several selectable averaging modes are available to enhance the
stability of the analyzer and eliminate anomalies if desired. Sample oxygen is analyzed very accurately. Response
time of 90% of full scale is less than 10 seconds on the 0-1 ppm range (actual experience may vary due to the
integrity of sample line connections, dead volume and flow rate selected).
Electronics:
The signal generated by the sensor is processed by state of the art low power micro-processor based digital
circuitry. The first stage amplifies the signal. The second stage eliminates the low frequency noise. The third stage
employs a high frequency filter and compensates for signal output variations caused by ambient temperature
changes. The result is a very stable signal. Sample oxygen is analyzed very accurately. Response time of 90% of
full scale is less than 10 seconds (actual experience may vary due to the integrity of sample line connections, dead
volume and flow rate selected) on all ranges under ambient monitoring conditions. Sensitivity is typically 0.5% of
full scale low range. Oxygen readings may be recorded by an external device via the 0-1V signal output jack.
Power is supplied by an integral rechargeable lead acid battery which provides enough power to operate the
analyzer continuously for approximately 60 days. An LED located on the front panel provides a blinking 72 hour
warning to recharge the battery. A 9VAC adapter (positive pole located on the inside of the female connector) can
be used to recharge the battery from a convenience outlet. The analyzer is designed to be fully operational during
the 8-10 hour charging cycle which is indicated by a second continuously lit LED.
Sample System:
The GPR-1200 MS is supplied with a bypass sample system which enables the user to isolate the sensor from
exposure to high oxygen concentration which results is a substantial increase is user productivity. The bypass
feature has two important features: One, the sensor can be isolated from exposure to high oxygen levels when
changing sample lines, during transport and during standby intervals making it ideal for mobile cart applications.
Two, it enables the user to purge newly connected gas lines of the oxygen trapped inside. The result is an analyzer
that comes on-line at ppb levels in a matter of minutes and provides users with a significant increase in
productivity.
However the sample must be properly presented to the sensor to ensure an accurate measurement. Users
interested in adding their own sample conditioning system should consult the factory. Advanced Instruments Inc.
offers a full line of sample handling, conditioning and expertise to meet your application requirements. Contact us
at 909-392-6900 or e-mail us at