Keithley 2182

Voltage and Temperature Measurements 2-25
High power switches — Heat is a factor in high power switching. As the temperature of the
switch increases, so does the contact resistance. In Figure 2-12 heat is generated in the switch
by sourcing a constant high current (i.e., 10A) through it.
Figure 2-12
Measuring switch contact resistance and temperature
The Model 2182 measures both the voltage across the switch contact and the temperature.
These measurements allow you to develop a resistance vs. temperature profile. With current
known and voltage measured, resistance can be calculated using Ohms Law: R = V/I.
Test Circuit
Switch
(DUT)
HI
HI
LO
LO
DCV1CH 1
CH 2
2182
Thermocouple
TEMP2
Constant
Current
Source
10A