Martel Electronics 235 - Manual (Page 80)

Fuse Testing
The calibrator employs fuses to protect the outputs and inputs in the
event the calibrator is improperly connected to external circuitry. It is
necessary to remove the covers in order to access the fuse panel. The
following tests should be performed BEFORE removing the covers to
determine if a fuse is actually blown.
Service Information
230/235 75
Fuse Type/
Location
Fuse
No.
Function Test
Input/
Output
Top PCB
230/235 F1 mA Input Connect an ohmmeter across the
input milliamps terminals. The
resistance should be approximately
5 ohms. If it reads open, the fuse is
probably blown. If it reads
significantly higher than 5 ohms, the
input dropping resistor may have
been damaged due to an overload.