Analytical Industries GPR-1600 MS Series PPB Oxygen Analyzer - Manual (Page 6)

Advanced Instruments Inc.
6
Installation
Gas Sample Stream: Ensure the gas stream composition of the application is consistent with the specifications and review the
application conditions before initiating the installation. Consult the factory to ensure the sample is suitable for analysis.
Contaminant Gases: A gas scrubber and flow indicator with integral metering valve are required upstream of the of the
analyzer to remove interfering gases such as oxides of sulfur and nitrogen or hydrogen sulfide that can produce false readings,
reduce the expected life of the sensor and void the sensor warranty if not identified at time of order placement. Installation of a
suitable scrubber is required to remove the contaminant from the sample gas to prevent erroneous analysis readings and
damage to the sensor or optional components. Consult the factory for recommendations concerning the proper selection and
installation of components.
Expected Sensor Life: With reference to the publish specification located as the last page of this manual, the expected life of
all oxygen sensors is predicated on oxygen concentration (< 1000 ppm or air), temperature (77°F/25°C) and pressure (1
atmosphere) in “normal” applications. As a rule of thumb sensor life is inversely proportional to changes in the parameters.
Deviations are outside the specifications and will affect the life of the sensor, with respect to Pico-Ion sensors avoid exposure to
oxygen levels above 1000 ppm. Failure to do will result in damage to the sensor.
Accuracy & Calibration: Refer to section 5 Operation. Analyzers equipped with Pico-Ion oxygen sensors have a maximum
range of 0-1000 ppm reflecting its high signal output capability, DO NOT CALIBRATE THE GPR-1600MS WITH AMBIENT AIR.
Materials: Assemble the necessary zero, purge and span gases and optional components such as valves, coalescing or
particulate filters, and, pumps as dictated by the application; stainless steel tubing is essential for maintaining the integrity of
the gas stream for ppm and percentage range (above or below ambient air) analysis; hardware for mounting.
Operating Temperature: The sample must be sufficiently cooled before it enters the analyzer and any optional components.
A coiled 10 foot length of ¼” stainless steel tubing is sufficient for cooling sample gases as high as 1,800ºF to ambient. The
maximum operating temperature is 45º C on an intermittent basis unless the user is willing to accept a reduction in expected
sensor life – refer to analyzer specification - where expected sensor life is specified at an oxygen concentration less than 1000
ppm oxygen for ppm analyzers and air (20.9% oxygen) for percent analyzers, but in all instances at 25°C and 1 atmosphere of
pressure. Expected sensor varies inversely with changes in these parameters.
Pressure & Flow
All electrochemical oxygen sensors respond to partial pressure changes in oxygen. The sensors are equally capable of analyzing
the oxygen content of a flowing sample gas stream or monitoring the oxygen concentration in ambient air (such as a confined
space such a control room or open area such as a landfill or bio-pond). The following is applicable to analyzers equipped with
Pico-Ion UHP and MS oxygen sensors, also refer to the analyzer’s specifications.
Sample systems and flowing gas samples are generally required for applications involving oxygen measurements below 1% and
at a pressure other than ambient air. In these situations, the use of stainless steel tubing and fittings is critical to maintaining
the integrity of the gas stream to be sampled and the inlet pressure must always be higher than the pressure at the outlet vent
which is normally at atmospheric pressure. Flow Through Configuration: The sensor is exposed to sample gas that must flow or
be drawn through metal tubing inside the analyzer. The internal sample system includes 1/8” compression inlet and vent
fittings, a stainless steel sensor housing with an o-ring seal to prevent the leakage of air and stainless steel tubing.
A flow valve upstream (flow indicator positioned downstream) of the sensor is recommended as a means of controlling the flow
rate of the sample gas, minimizing potential air leaks and providing optimum performance.
Caution: The superior performance characteristics of the Pico-Ion Series oxygen sensor include:
¾ LDL (lower detectable limit) below 10 ppb,
¾ Excellent stability,
¾ Fast recovery from high oxygen upset conditions,
¾ 24 month operating life,
¾ No maintenance
Flow Rate: For optimum performance, a flow rate of 1 SCFH at 30 psig is recommended.