Advanced Instruments Inc.
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.
Additional features of the micro-processor based electronics include manual or auto ranging, isolated 4-20mA signal
for signal output and range ID. Whenever the analyzer is calibrated, a unique algorithm predicts and displays a
message indicating a ‘weak sensor’ suggesting the sensor be replaced in the near future.
Users interested in adding their own sample handling or conditioning system are encouraged to consult the factory
to ensure all applicable conditions are addressed to ensure proper operation of the analyzer. 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
Sample
System
The GPR-IN190 is designed to be integrated into a larger analyzer system and provide users with maximum
flexibility, and, therefore is not equipped with a sample system. 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
However, for optimal performance after exposing the sensor to air or elevated oxygen levels in terms of:
1) bringing the analyzer back online, and,
2) maximizing the service life of the sensor by isolating the sensor
Advanced Instruments recommends the user employ one of the following ‘bypass sample system’ designs illustrated
below. Preference is given to the illustration on the left because it is the surest and simplest approach.
The ‘bypass sample system’ is optimal, however, it is not required. For example, deleting the 3-way valve from the
illustration on the right enables the user to isolate the sensor but lengthens the time required to bring the analyzer
online. The bypass feature diverts the flow of sample gas containing high concentrations of oxygen around the
sensor – which when the valves are operated properly remains in an atmosphere containing a low concentration of
oxygen, less than 100-200 PPM. The source of the atmosphere with the low concentration of oxygen can be either be
a zero gas or sample gas is not important - only the oxygen concentration is important. Without the bypass feature,
the sensor still can be isolated but not as easily and the best the user can do when connecting a new gas line is start
the flow of sample gas (to purge the air trapped inside the line) several minutes before connecting to the analyzer.
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