GE moisture.IQ, User Manual

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Chapter 8. Troubleshooting
96 moisture.IQ User’s Manual
8.2 Common Problems
If the moisture.IQ measurement readings seem strange or do not make sense, there may be a problem with the
probe or the process system.
Table 12 below contains some of the most common measurement problems.
Table 12: Troubleshooting Guide for Common Problems
Symptom Possible Cause System Response Action
Accuracy of
moisture
sensor is
questioned. Insufficient time for
system to equilibrate Probe reads too wet
during dry down
conditions, or too dry
in wet up conditions. Change the flow rate. A change in dew point
indicates the sample system is not at
equilibrium, or there is a leak. Allow sufficient
time for the sample system to equilibrate and
the moisture reading to become steady. Check
for leaks.
Dew point at sampling
point is different than the
dew point of the main
stream. Probe reads too wet or
too dry. Readings may be correct if the sampling point
and main stream do not run under the same
process conditions. Different process
conditions cause readings to vary. If sampling
point and main stream conditions are the
same, check sample system pipes, and any pipe
between the sample system and main stream
for leaks. Also, check sample system for
adsorbing water surfaces, such as rubber or
plastic tubing, paper-type filters, or condensed
water traps. Remove or replace contaminating
parts with stainless steel parts.
Sensor or sensor shield
affected by process
contaminants (refer to
Basic Hygrometry
Principles
).
Probe reads too wet or
too dry. Clean the sensor and the sensor shield as
described in
document 916-064 , Basic
Hygrometry Principles. Then reinstall sensor.
Sensor is contaminated
with conductive particles
(refer to
Basic Hygrometry
Principles ).
Probe reads high dew
point. Clean the sensor and the sensor shield as
described in document 916-064
, Basic
Hygrometry Principles . Then reinstall sensor.
Sensor is corroded (refer to
Basic Hygrometry
Principles
).
Probe reads too wet or
too dry. Return probe to factory for evaluation.
Sensor temperature is
greater than 70°C (158°F). Probe reads too dry. Return probe to factory for evaluation.
Stream particles are
causing abrasion. Probe reads too wet or
too dry Return probe to factory for evaluation.