Introduction; Qualification Tests; Operation - Wahl Heat-Prober 392AHP User Manual

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Heat-Prober Platinum-RTD Thermometers User Manual
1.0

INTRODUCTION

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The Digital Heat-Prober is a precision instrument for measuring temperature. It uses the
latest microprocessor technology to provide conformity to 0.1°F to the IEC751 and ITS90
platinum resistance curve. It provides the certainty of digital display and the precision of 0.1°
resolution. It is a complete instrument with its own rechargeable battery power supply and
recharger for the 392HP, 392E, 392EX, 392M and 392MX, standard 9 volt replaceable battery
for the 392EVX and 392VX and a group of interchangeable probes designed for rapid and
accurate temperature measurement.
The probes and meters are individually calibrated and then tested together in temperature
baths before being sent to the user.
The LED display is 0.33" high with high brightness for good readability in all light conditions.
To minimize power drain, the display is multiplexed. The LCD display is 0.4" high with
excellent contrast.
A large portion of the circuit is designed with low power C-MOS components. The result is a
design which provides a low power drain operation, which allows operation for 8 hours per
charge for the 392E, 392EX, 392M, and 392MX meters. Battery life is 50 hours for the
replaceable battery used in the 392EVX and 392VX meters. Continuous operation as well as
concurrent battery charging is possible by utilizing the recharger.
The instrument contains as a standard, the unique Wahl "Maxi Temp" digital peak hold circuit
which gives the user the option to hold the highest temperature sensed. The peak-hold circuit
is achieved by the microprocessor scanning the probe input temperature to determine the
peak versus an analog circuit.

1.1 Qualification Tests

This instrument has been extensively tested under temperature environments from -40 to
+140°F, subject to 4-foot drop test, battery life test and running life tests.
2.0 OPERATION (See Figure 2-1)
Insert probe into jack at top. Turn on the switch at the left. The switch is 3- position; the lower
detent is marked "N" for normal temperature monitoring, the middle detent is "OFF" and the
upper detent is marked "P" for use of the "Maxi Temp" Peak hold circuit. This will track
temperature and hold the highest attained reading. The room temperature will be displayed in
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°C or °F as indicated. If "L", " ", or "Lo Bat" appears or if there is no reading, this indicates
the battery is discharged. Recharge the unit by inserting the recharger in an appropriate
power source, 50-60 Hz wall outlet plug in the recharger jack to the receptacle on the left side
of the unit, or in the case of the 392EVX or 392VX, replace the battery. For fastest recharging
time, turn POWER for the instrument OFF. Charge for 6-7 hours.
Make measurements with sensor probe as required. Turn off switch when measurements are
complete to conserve battery life.
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