The resistance value is decreasing

QI'm measuring fuse resistance using the RM3544A. However, the resistance value decreases gradually. What is the cause?

A

This is due to one of the following reasons:

1.  Effect of temperature
The RM3544 measures resistance by flowing constant current using the 4-terminal method.
The resistance changes because of the change in temperature via heat on DUT and/or the environment (air-conditioning, wind, etc.)

2.  Contact condition
The contact pressure of measurement probes has changed.