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•
Dry-wells have inserts
that are interchangeable
and have a variety of hole
patterns to accommodate
various probe sizes.
•
To achieve published
performance levels, the
insert’s hole size should
be no more than a few
hundredths of an inch
larger than the probe being
calibrated.
•
Avoid placing fluids in
a dry-well. If fluids are
required, use a Micro-Bath
instead.
•
If climbing a ladder is
required, dry-wells are
safer than baths, and
handheld dry-wells may be
the most convenient.
TECH
TIPS
Additional resources
For more in depth information
about this application check out
these videos and application notes
from Fluke.
How to Calibrate an RTD
Using a Dryblock Calibrator
webinar
914X Field Metrology Wells
Video Series
Industrial Temperature
Calibrators Workload Matrix
To perform the test:
Isolate the sensor from the process.
Fully immerse the sensor into a precision temperature source, such as a
dry-well or bath capable of covering the required temperature range.
For best accuracy, also fully immerse a temperature standard into the dry-
well or bath for comparison (the process version of Field MetrologyWells
have a built-in precision readout for the temperature standard).
To check the calibration of the RTD separately from the control system
temperature indicator, disconnect the RTD from the electronics.
Connect the RTD to a precision instrument capable of measuring resis-
tance. (The process version of Field MetrologyWells have the required
electronics built in.)
Adjust the temperature of the bath or dry-well to each of the test points
(With Field MetrologyWells these test points can be preprogrammed and
automated.)
At each test point record the readings of the temperature standard and
RTD.
If measuring the RTD separate from its measurement electronics, compare
the measured resistances to the expected resistance from the applicable
temperature table. Otherwise, compare the reading on the instrument display
to the reading of the temperature standard (which may be the dry-well).
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100.00°
C
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100.00°
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ENTER
MENU
100.2° C
47
Temperature Applications