User Manual
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4.2.3 Types of Temperature Sensors
The instrument is designed to use two types of temperature input: Pt and Analog Input. Touch
the T.SENS key, the following menu options will be displayed:
Pt: Provided temperature probe.
AnLG_In: Linearly converts probe input voltage (0 to 2 V) into temperature based
on Analog Input settings. See 4.2.6 Analog Input.
4.2.4 Temperature Correction (TC) Function
The resistance of a material changes with temperature according to the material’s temperature
coefficient. The temperature correction function compensates for changes in resistance due to
changes in ambient temperature. The measured resistance is displayed as if it was measured at
the preset temperature.
R
t
- Resistance measured under the current ambient temperature
R
t0
- Resistance corrected to the preset temperature
t
0
- Preset temperature
t
- Current ambient temperature
t0
- Temperature coefficient of the material
Example:
A copper DUT measured 10.393 Ω at 30 °C. Coppers temperature coefficient is 3930 ppm / °C at 20 °C.
4.2.5 Temperature Conversion (∆t) Function
This function converts the change in a DUT’s winding resistance into a change in temperature.
The user measures the DUT’s resistance and surface temperature before operation (cold) and
measures the DUT’s resistance and ambient temperature after the element has heated up (hot)
from operation and is no longer powered. ∆t represents an estimate of the DUT’s change in
temperature between the cold and hot state. This is typically used to measure a motor’s
temperature or the inside of a coil after heating up from operation and power is removed.
t
– Temperature difference between the initial cold and final hot state.
R
1
– Resistance at the start of the thermal test.
R
2
– Resistance at the end of the thermal test.