Datasheet
GMC-I Messtechnik GmbH  7
Several well-tuned protection means protect the instrument against 
damage through improper handling and overload within the specified 
limit values for overload:
• Overdimensioned precision resistors 
• Melting fuse in conjunction with protective power diodes 
• Overvoltage arrester 
The instrument operates independent of the mains on a commercially 
available 9 V flat cell battery. Thanks to the low power consumption of 
the electronic components, a long battery life is assured.
The rugged design of the multimeter assures fine protection in the 
case of rough mechanical duty. In closed condition, the instrument 
offers additional mechanical protection for the measuring unit and the 
indicating unit. The connection sockets are protected against acciden-
tal contact. Both the special measuring leads the connection plugs of 
which are protected against accidental contact (lead set KS17-2) and 
all measuring leads with conventional banana plugs (4 mm diameter) 
can be used.
4 Operation
4.1 Controls
ON/OFF switch
The toggle switch is used to turn the instrument on and off. This switch 
should be switched to the "OFF" position when the instrument is not 
operated for extended periods of time in order to avoid unnecessary 
load on the battery. Apart from that, even a leakproof battery may leak 
when the instrument remains turned on for several days with a dis-
charged battery. Damages caused by leaking batteries are not cov-
ered by the instrument warranty. 
When the instrument is closed, the battery is automatically discon-
nected.
Range switch
The multimeter has only one rotary switch. All measuring ranges are 
selected with it. Without disconnecting the measured variable, it is 
possible to switch from the DC voltage ranges to the corresponding 
AC voltage ranges or from the DC current ranges to the corresponding 
AC current ranges. The measuring circuit is not interrupted when 










