ThermoProbe TP7 User Manual
Page 2
REPLACING THE PROBE ASSEMBLY
When attaching a new probe assembly to circuit, it is necessary
to pay attention to the polarity of the probe.
Black Wire (shielding with shrink wrap) = (-)
White Wire (signal lead) = (+)
Polarity markings are located on the circuit board in front of the
finger connector. See illustration.
Reversed wires will inhibit proper probe grounding and may
cause false readings.
If a probe assembly is replaced with one of the same length, the
calibration will be within + 0.2 °F at 32 °F and within +0.6 °F
at 200 °F. It is recommended that a recalibration be performed
to make the instrument as accurate as possible.
CALIBRATION
The TP7 design allows extended calibration periods. If
accuracy is not within specifications check cable integrity and
inspect the circuit board for possible corrosion, particularly near
the cable terminals. Calibration adjustments will not properly
correct these problems.
To verify/calibrate the instrument to the best possible accuracy
over a wide range, the following items are necessary:
-A certified thermometer.
-A circulated refrigerated bath, with a temperature near:
32.0 °F/ 0.0 °C (Bath 1)
-A circulated hot bath with a temperature:
190-200 °F /88-93°C (Bath 2)
-Small flat head adjustment screwdriver or similar tool.
1. Remove the 3 faceplate screws and lift assembly from housing.
2. Using the illustration (to the right) find the adjustment trims.
3. Adjust the ZERO with the probe assembly in Bath 1.
4. Adjust the SPAN with the probe assembly in Bath 2.
5. Repeat several times or until no adjustment is necessary.
PROBE WIRE
TERMINALS
(
Other Side)
SPAN
ZERO
95.8F
- +
F / C
SELECTOR
(Other Side of
Board)
FACEPLATE-CIRCUIT BOARD MODULE
AUTHORIZED REPAIR
:
It is recommend that service done beyond
the scope of this article be presented to
ThermoProbe Inc. or one of its distributors.
Any servicing by unauthorized parties may
void the Intrinsic Safety and the warranty.
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112-A Jetport Drive
Pearl, MS 39208 USA
Voice: +1 601-939-1831
Fax: +1 601-355-1831
www.thermoprobe.net