AM1860/1850 Standard Platinum Resistance Thermometer
User’s Guide
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3 General Operations
3.1 Connecting to the readout device
The AM1860/1850 is equipped with a four-wire cable (see Figure
1). Four lead wires are used to cancel lead wire resistance. For best
results, the readout device should be equipped to handle four-
terminal resistors. The lead wires can be distinguished by
insulation colors. Lead wire pairs attached to each end of the
sensor are identified by red/black and white/blue insulation.
3.2 Drive Current
AccuMac recommends 1mA as drive current to ensure the best
measurement.
3.3 Stability of Readings
To achieve the best accuracy, allow sufficient time for PRT to
stabilize before taking the readings.
3.4 Immersion Requirements
Stem effect can cause measurement errors due to heat lost or
gained by the sensing element through the thermometer stem. To
Figure1
Blue
Yellow
White
Red
