Ingersoll-Rand HC-103, User Manual

Page: 83 / 128

INSTRUCTION MANUAL
Sahara Moisture Transmitter
Reference IR-085 Rev 3
Page 15 of 16 01/10/2014
VIII. Helpful Information (continued)
D. Contaminants
1. Industrial gases often contain fine particulate matter. Materials such as carbon
particles, salts, rust particles, polymerized substances, chemical liquid droplets,
dust, molecular sieve, or alumina dust can be present. Their effect on the
operation of the sensor is described below.
a. Non-conductive Particulates (i.e. molecular sieve particles, liquid droplets of
hydrocarbons, oil droplets)
i. In general, non-conductive liquids condensing on the sensor will not
seriously hinder the performance of the sensor. A slower response to
moisture changes will probably be observed due to the liquids acting as
a barrier decreasing the rate of transport of the water vapor, hence,
hindering the response time.
ii. Particulate matter of high density and at high flow rates may cause
abrasion or pitting of the sensor surface. This can cause severe change
in calibration and, in extreme cases, cause failure of the sensor. A
stainless steel shield is supplied with the sensor to minimize this effect.
However, in severe cases, it is advisable to filter the incoming stream
with filters of teflon or stainless steel.
iii. On rare occasions, non-conductive particulate material may become
lodged under the contact arm of the sensor, creating an open circuit. If
any of the above occurs, Ingersoll-Rand recommends return of the
probe to the factory for cleaning.