Raytech USA, Inc.
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20
TEMPERATURE MEASUREMENTS
9 – 0
The system allows up to three (3) temperature probes to be used with the system for the purpose
of recording temperatures. Optional Part Number: TP 01, can be purchased for this purpose.
Recording the temperature of the device under test is highly recommended due to the
characteristics of the increase of resistance of a metallic object as its temperature increases.
There are temperature compensation tables for Copper and Aluminum available to calculate the
conversion factor to a known reference temperature.
The WR50-12 is a very accurate and precise test system. To take full advantage of this high
accuracy, the temperature of the device under test should be recorded.
The TP 01 temperature probe is mounted to a flexible extension cable that plugs into the front
panel of the WR50-12. This option enables the User to record the ambient temperature and/or
the actual temperature of the device under test.
The WR50-12 will automatically sense when the optional temperature probes, TP-01, are
connected to it. The temperature will be displayed on the instrument screen during a test and
will appear when a printed report is requested. The temperature, as well as the test results, can
be saved into memory.
TEMPERATURE CORRECTION
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The WR50-12 can correct the measured values regarding the temperature.
To activate this feature, press “Setup” and then “Temp. Correction” .
In this example, the measured object is copper and will be corrected to 25 Degrees Celsius
based on the temperature on Temperature channel 1.
If you do not have a Raytech Temperature probe (TP-01), activate the “Ext” box and fill in the
temperature you measure with your other temperature probe or measuring device.
The correction follows the formula:
Rs = Rm[(Ts+Tk)/(Tm+Tk)] where
Rs
is resistance at desired temperature, Ts
Rm
is measured resistance
Ts
is desired reference temperature
Tm
is the temperature at which resistance was/is measured
Tk
is 234.5 for copper, 225 for aluminum (aluminum may be as high as 240)
If you are used to a correction with “alpha25” you can calculate the Tk by the formula:
Tk=(1/alpha25)-25
If you are using another Tk then the standards for cooper or aluminum, activate the box
“User defined” and input the Tk in the box below.
