CFM-88L 07/20/0910
6.0 TEMPERATURE MEASUREMENT
6.1 TEMPROBE
Temperature measurements are obtained using the TemProbe temperature probe. The TemProbe may be plugged directly
into the temperature input jack on the back of the meter. Since this receptacle is keyed, the plug of the TemProbe sensor
must be correctly aligned for proper insertion. The release button on the side of the TemProbe must be pressed to
disconnect the TemProbe from the meter.
The “settling in” time required for the thermistor to stabilize at the temperature of the air being measured will vary with the
temperature differential between the TemProbe and the air, and also with the velocity of the air across the probe. The
“settling in” time is typically less than for a standard glass thermometer.
After turning the meter on, press the MODE key until TEMP is briefly displayed, followed by the units and READ. Then,
using the retractile cord if necessary, place the TemProbe sensor in the medium to be sampled. Press the READ key to
take a temperature reading. If the TemProbe is not installed on the meter, or if it is open circuited (defective), the display
will read NO PROBE.
FIGURE 6.1 ADT442 TEMPROBE
Accuracy is ± 0.5
/F from 32/F to 158/F with a resolution of 0.1/F using the ADT400 Series TemProbes. Measurement
range for the ADT446 TemProbe is -20
/F to 180/F and -67.0/F to 250.0/F for the other ADT400 Series TemProbes. Meter
will display OVER TEMP or UNDER TEMP if the probe is exposed to temperatures beyond this range. Maximum
recommended safe exposure range is -100
/F to 250/F and the probe accuracy may be effected by exposure beyond this
range. Do not expose plastic base of the TemProbe or the extension wand to temperatures above 200
/F.
NOTICE: The use of more than one temperature cable extender may reduce the meter reading by a non-linear degree
depending on the combination of cable type, length and TemProbe temperature. This is due to the added resistance of
the additional cable(s). This effect is likely to be negligible at very low temperatures, but may be
$ 0.15/F per additional
cable extender at 154
/F. The offset correction(s) must be determined by comparing readings taken with and without the
extender cables at the temperature(s) to be measured.
6.2 AIRDATA MULTITEMP
The MT-440K MultiTemp comes with six insertion probes, two surface probes, one eight-position switch, and a small
carrying case.
Plug the single cord on the bottom edge of the MultiTemp into the temperature input jack on the back of the AirData
FlowMeter. Up to eight temperature probes (each with a 12' cord) can be connected into the eight small, numbered
temperature input jacks on the top edge of the switch box. The jack numbers correspond to the eight switch position
numbers surrounding the switch.
Place each of the temperature probes in the system as required and allow the probe temperatures to stabilize. A typical
system testing application is shown in Figure 6.2. Set the meter for the temperature function as discussed in Section 5.0
USING THE AIRDATA FLOWMETER. Set the MultiTemp for switch position #1 and take a reading for the probe connected
to temperature input jack #1. Turn the switch to position #2 and take a reading for temperature jack #2. Continue for as
many of the eight temperature jacks as needed.
Additional points may be measured in the same measurement sequence by using more than one MultiTemp switch unit
connected in series (piggybacking). Connect the primary MultiTemp module to the meter as described above. Connect
the output jack of each secondary MultiTemp to the input jack of the primary MultiTemp using plug adapter P/N PA-447.
Each switch position of the primary MultiTemp can support up to eight switch positions on a secondary MultiTemp. The
temperature probes used with the MultiTemp and AirData FlowMeter are typically interchangeable.
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