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Maintenance
Internal Temperature
Sensor (rdt1)
Calibration
Should the bath fluid temperature display disagree with your calibrated refer-
ence thermometer, the internal temperature sensor (rtd1) may need calibration.
Do not pick calibration points that are outside the safe operating limits of the
fluid in your application. For example with water, 90°C and 5°C would be
typical calibration points.
NOTE:
If it is more convenient, the low-end calibration can be performed before
doing the high-end.
Run the bath to a suitable high-
end calibration point. Place a
calibrated reference thermometer
in the bath. Ensure the fluid
temperature is stabilized. Press
and hold the NO button and then
press the YES button three
times. Release the NO button.
The controller will display
CAL
.
Press YES and the controller will
display
rdt1.
Press YES again
and the controller will display
r1 H.
Press YES again and the
controller will alternately flash
r1 H
and the current probe temperature. Use the arrow
buttons to adjust the temperature to match the reference
thermometer.
Press the SCROLL and NO buttons as shown until
StorE
is displayed, press YES to accept the new value,
press No to abort it.
Repeat for the low-end temperature. Run the bath to a
suitable low-end calibration point. At the
r1 L
display use
the arrow buttons to adjust the temperature to match a
calibrated reference thermometer.
Press the SCROLL and NO buttons as shown until
StorE
is displayed, press
YES to accept the new value, press NO to abort it.
NOTE:
Both the high and low temperatures must be entered for a valid calibra-
tion. If power is lost before the procedure is complete, critical data needed for
the calculation of calibration parameters will be lost. After pressing the YES
button at the
StorE
prompt wait several seconds before proceeding to ensure
that a bad calibration message does not appear. Premature use of the keypad
after pressing the YES button may cancel the bad calibration error message.
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Yes
No
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Yes
Yes
No
No
No
No
3ROG
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
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No
No
No
No
No
No
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Optional Display
Optional Display
rtd3 is used to calibrate the
refrigeration system, contact
Thermo.
