Analytical Industries GPR-2500 S Oxygen Analyzer - Manual (Page 6)

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. Note: In natural gas applications such as extraction and transmission, a low voltage current is
applied to the pipeline itself to inhibit corrosion. As a result, electronic devices can be affected unless adequately
grounded.
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. Deviations are outside the specifications and
will affect the life of the sensor. As a rule of thumb sensor life is inversely proportional to changes in the
parameters.
Accuracy & Calibration: Refer to section 5 Operation.
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 in a control room or an open area such as a
landfill or bio-pond). The following is applicable to analyzers equipped with fuel cell type oxygen sensors. With
respect to analyzers equipped with Pico-Ion UHP and MS oxygen sensors, refer to the analyzer’s specifications.
Inlet Pressure: The GPR-2500S is designed for in-situ ambient or area
monitoring and has no sample system because the sensor is intended to be
exposed directly to the surrounding ambient atmosphere which it is sampling and
to operate at atmospheric pressure, however, slightly positive pressure has
minimal effect on accuracy.
Further, applications situations may dictate that the sample be transported from a
semi-sealed area to a safe area where the analyzer is located. In these cases the
analyzer can be readily adapted to include optional pumps, tubing and connection
fittings. Users interested in adding their own sample conditioning system should
consult the factory.