Maintenance/Repair - Wahl Heat-Prober 392AHP User Manual

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Heat-Prober Platinum-RTD Thermometers User Manual
5.0

MAINTENANCE/REPAIR

The Heat-Prober instrument may be recalibrated, or adjusted for a particular probe in the field
by following the directions in Section 6.0. However, it is recommended that calibrations and
repair be done at the factory. Return the Heat-Prober in its foam package with a description of
symptoms, and a repair estimate will be made for your approval.
The best way to check the functioning and calibration condition of the Heat-Prober is to use the
Wahl accessory Calibrator Models Numbers CAL392HT or CAL392LT, which plug right into the
probe connection and provides five key calibration points. (See Figure 5-1). The calibrator has
a set of precision-wound resistors which are measured at the factory against a NIST traceable
standard. The WAHL calibrator is a convenient instrument to determine whether a problem is in
the probe or the meter. If the meter checks on all 5 calibration points within tolerance, for
example, then one will know that the probes are at fault.
The most common maintenance problem is battery failure, evidenced by no dis- play. NiCad
battery failure and prevention of this problem are noted in Section 2.4. If you suspect a dead
battery:
1. Plug in the recharger and allow to recharge for 12 hours. If batteries fail to recharge after this
time:
2. Open the battery compartment lid on the bottom of the instrument. Unplug the battery. Using
a DVM, check voltage with a 16 ohm load. If the voltage drops rapidly it indicates a fault in the
battery.
3. With the convenient detachable plug, the battery pack Model Number 11681-1 can be easily
replaced by a new one. For emergencies it is possible to use a 9-volt transistor battery to power
the Heat-Prober (but one must make a special connection). Expected continuous running time
on 9- volt alkaline battery is about 3 hours, for LED display or 6 hours for LCD display.
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