Fluke 9107 - Manual (Page 27)

7.3 Setting the Temperature
Section 8.3 explains in detail how to set the temperature set-point on the cali-
brator using the front panel keys. The procedure is summarized here.
(1) Press “SET” twice to access the set-point value.
(2) Press “UP” or “DOWN” to change the set-point value.
(3) Press “SET” to program in the new set-point.
(4) Press “EXIT” to return to the temperature display.
When the set-point temperature is changed the controller will switch the well
heater on or off to raise or lower the temperature. The cycle indicator, a two
color LED, will also indicate on (red and heating) or off (green and cooling).
The displayed well temperature will gradually change until it reaches the
set-point temperature. The well may require 5 to 20 minutes to reach the
set-point depending on the span. Another 5 to 10 minutes is required for the
temperature to stabilize.
7.4 Calibrating Probes
The dry-well block provides a constant temperature environment in which
probes may be compared. The probes inserted into the block may be compared
to the well temperature displayed on the front panel of the calibrator. The
probes should be inserted the full depth of the well since the temperature at the
bottom of the well will most closely agree with the displayed temperature.
For greater accuracy the probes may be compared to a reference thermometer
inserted into the block. The reference thermometer may be inserted into one
hole while the probes to be calibrated are inserted into another. The drawback
to this method is that because of temperature variations throughout the block
there may be a small temperature difference between one hole and another
which can cause errors.
Using the same hole for the reference thermometer and the test probe may have
better results. This however requires switching the probes which takes more
time. One must allow a few minutes after inserting the probes for the tempera-
ture to stabilize before making measurements. Because of temperature varia-
tions along the length of the well, best results are obtained when comparing
probes of similar construction and inserting them the same depth into the well.
22 Hart Scientific
7 General Operation