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16.
COMMONLY ASKED QUESTIONS
Below are some commonly asked questions with answers and possible solutions.
Q:
“What if my calibration check results are out of range?”
A:
Perform a sensor calibration.
The Computrac
®
VAPOR PRO
®
Rx
self-adjusts
the internal calibration factors to the high precision moisture sensor, due to varying
conditions (temperature, product accumulation in the flow system, component wear, etc.).
Over time, this may cause the overall calibration to drift slightly. Since sensor calibration
is easily performed, daily verification is recommended.
Q:
“How do I dry the instrument after an upset?”
A:
In case the instrument has been flooded with moisture, either by running a very
wet sample, or by exposure to a wet atmosphere, it will be necessary to dry the entire flow
system before normal operation can be resumed.
•
Inspect the tubing, the needle, the sensor block, and if a filter is used on the
instrument, inspect the filter also to be sure that no contaminants are present that
might absorb and release large quantities of water. If contamination is present,
replace the contaminated parts with new parts.
•
Confirm that the carrier gas supply is dry. If there is any doubt about this, employ a
drying cylinder in line with the gas supply before connecting it to the instrument gas
input fitting. We highly recommend using an in-line desiccant to prevent unexpected
contamination or to minimize any variation in carrier gas moisture levels.
•
Go to the memory start list and select
*DRYNESS TEST*
Press
[Start]
.
•
Periodically examine the rate graph display to see if the moisture rate is falling.
Normally, the rate will begin to decline after 30 seconds, and eventually will fall
to less than 1
µ
g/sec at which point, testing can resume.
If the moisture rate remains at a very high level until the end of the test, a source
of water is present in the system and must be removed before the system will dry
out.
