Addendum: HHM29-IR
A
1-2
In order to make infrared temperature measurement:
1. Disconnect any thermo-couple probe from the meter.
2. Set the slide switch to IR.
3. There is a rectangular door in front of the multi-meter that
covers the laser beam aperture. Open the door by rotating it.
4. The field of view of the multi-meter should fall within the area of
the target being measured (Fig. 1). Refer to the field of view vs.
distance chart (Fig. 3).
5. There is a single turn
potentiometer on the
right side of the meter for
emissivity adjustment.
Set the Emissivity
accordingly.
6. There is a momentary
switch on the right side
of the multi-meter. Press
and hold momentary
switch to turn on the
laser and infrared
measurement. A red LED
in front of the meter
turns on to indicate the
laser is on. A red laser dot indicates the center of the multi-meter’s
field of view. Using the laser sighting, aim at the target and measure
the temperature.
While measuring temperature via. Infrared, the thermocouple input
becomes thermocouple output proportional to the temperature
measured.
This thermocouple output (K type) can go to a strip chart recorder
for temperature profiling. See Figure 2.
The line of sight of the multi-meter does not coincide with that of
the laser sighting. There is a fixed distance of 0.610" (15.5 mm)
between the two lines of sights as shown in Fig. 3. When aiming at
targets using the laser sighting, the 0.610" distance should be taken
into account.
The main multi-meter uses a 9 volts battery to operate. The infrared
measuring circuit is powered by two Lithium AA (1.5 VDC) size
batteries. When the lithium batteries go low, the multi-meter beeps.
This audible beep indicates that the lithium batteries have to be
replaced.
In order to determine an unknown target Emissivity:
To Strip Chart
Recorder
To "K" Type
TC Input
"K" Type TC Wire
Figure 2 - Recorder Connections
