© Isothermal Technology
Page 55 of 102
923 milliK manual - issue: 1.10
Use the same 4-wire connection as is employed with PRTs so as to eliminate the effect of
cable resistance on the measurement:
4
5
6
1
2
I-
I+
V+
V-
3
+tc
THERMISTOR
NC
NC
The relatively high resistance of thermistors means that they are used with much lower sense
currents (2µA on milliK) than PRTs/SPRT and the effect of the cable resistance is much
lower. Thermistors are therefore sometimes supplied with only 2-wire connections, in which
case they can be connected to the milliK as follows:
4
5
6
1
2
I-
I+
V+
V-
3
+tc
THERMISTOR
NC
NC
4.3 Connecting Thermocouples to milliK
In order to connect thermocouples to your milliK, fit a suitable miniature thermocouple plug
(conforming to ASTM 1684-05) and connect it to one of the thermocouple sockets on the
front panel. The plug should be a copper type (contacts made of copper) if using a
thermocouple with an accessible reference junction that is measured by a separate
thermometer (external compensation) or in an ice point (0°C reference junction temperature).
If you wish to use internal reference junction compensation, fit a thermocouple plug that
matches the thermocouple type (contacts made of the same metal/alloy used in making the
thermocouple), the reference junction is then formed inside the connector.
