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KAHN INSTRUMENTS, INC.
885 Wells Road, Wethersfield, CT 06109
Tel: 860-529-8643; Fax: 860-529-1895
E-mail: [email protected]
www.kahn.com
Try to avoid too many "T" pieces or unnecessary tubing. Where possible,
build up the sampling pipe specifically for the job and do not use tubing
previously installed for another application. Dead space in sample lines
increases response time by holding water molecules which are more slowly
released to the passing gas sample.
c)
Remove any particulate matter or oil from the gas sample.
Particulates entering the sensor measurement chamber will cause
contamination of the sensitive optical components, this will result in the
need for more frequent cleaning of the sensor optics. If particulates such as
desiccant dust or rust are possible, use a particulate in-line filter. Kahn
instruments' technical sales staff will be pleased to give advice.
d)
Use high quality fittings.
We recommend that, wherever possible, stainless steel tubing and fittings
be used. This is particularly important at low dewpoints since other
materials have hygroscopic characteristics and absorb moisture in the pipe
walls. Absorbed moisture will slow down measurement response and, in
extreme circumstances, give false dewpoint readings.
For temporary applications, or where stainless steel tubing is not feasible,
use high quality thick-walled PTFE pipe which exhibits similar
characteristics to stainless steel.
Always use the shortest run of tubing possible between two points. Use the
smallest diameter tubing possible to reduce response time. However, take
care not to induce pressure differentials by aiming for too high a flow-rate
through small diameter tubing. A sample flow-rate between 50 and 200
cm
3
/min. (0.05 and 0.2 l/min.) will be satisfactory for the Series 4000
Integrale
Dewpoint Hygrometer to operate correctly.
4.3
Which Gases to Measure?
The Series 4000
Integrale
Precision Hygrometer, by nature of its design, is suitable for
measurement of the moisture content of a wide variety of gases. In general, if the gas (in
conjunction with water vapor) is not corrosive to base metals then it will be suitable for
measurement by the Series 4000
Integrale
Precision Hygrometer. However, gases
containing entrained solids should be filtered before presentation to the Series 4000
Sensor.
