Advanced Instruments Inc.
10
TransmitterInstallationConsiderations
ontentsofsamplestreamC
Ensure the gas stream or composition of the controlled atmosphere of the application is consistent with the
specifications and review the application conditions before initiating the installation. Consult the factory if
necessary to ensure the sample is suitable for analysis.
Samplepressureandflow ly
the oxygen
ntrolled atmosphere.
steel
ded for
am of the sensor is recommended for controlling
possibility of leakage for low ppm measurements,
nsor to control the flow rate and position a flow indicator
regulator (with a metallic diaphragm) is recommended
t pressure between 5-30 psig.
re-Atmosphericorslightlynegative
g oxygen in a glove box), an optional external
sensor to draw the sample from the process, by the
stream of the sensor to control the flow through the
pheric pressure, push the sample through the sensor housing by positioning the
lication, when pump is used, set the flow
to
SCFH which generate backpressure on the sensor.
All electrochemical oxygen sensors respond to partial pressure changes in oxygen. The sensors are equal
capable of analyzing the oxygen content of a flowing sample gas stream or monitoring
concentration in a co
Sample system for measuring oxygen in a flowing gas samples is generally required. The use of stainless
bing and fittings is critical for maintaining the integrity of the gas stream to be sampled tu
A flow indicator with an integral metering valve upstream of the sensor is recommended as a means of
ontrolling the flow rate of the sample gas. A flow rate of 2 SCFH or 1 liter per minute is recommenc
optimum performance.
Application-SamplePressure-Positive
A flow indicator with integral metering valve positioned upstre
the sample flow rate between 1-2 SCFH. To reduce the
position a good quality needle valve upstream of the se
downstream of the sensor. If necessary, a pressure
upstream of the flow control valve to regulate the inle
Application-SamplePressu
For sample at atmospheric pressure, (except when measurin
sampling pump should be positioned downstream of the
sensor and out to atmosphere. Install a flow meter down
sensor housing.
For sample at less than atmos
pump and the needle valve upstream of the sensor. In either app
approximately at 1-2 SCFH.
NOTE: If pump loading is a consideration, a second throttle valve on the pump’s inlet side may be necessary
provide a bypass path so the sample flow rate is within the above parameters.
Recommendations to avoid erroneous oxygen readings and damaging the sensor:
• Assure there are no restrictions in the sample or vent lines
• Avoid drawing a vacuum on the sensor that exceeds 14” of water column pressure
• Avoid excessive flow rates above 2
• Avoid sudden changes in the sample pressure.
• Avoid the collection of liquids or particulates on the sensor, they block the diffusion of oxygen into the
sensor.
Removalofmoisture&particulatesfromsamplegas
stallation of a suitable coalescing and/or particulate filter is required to remove condensation, moisture and/or
articulates from the sample gas to prevent erroneous analysis readings and damage to the sensor. Moisture
nd/or particulates do not necessarily damage the sensor, however, collection on the sensing surface can
lock or inhibit the diffusion of sample gas into the sensor resulting in a reduction of sensor signal output – and
e appearance of a sensor failure when in fact the problem is easily remedied by blowing off the liquid
ondensed on the front of the sensor.
In
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th
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