Operation Manual
GMC-I Messtechnik GmbH 9
Safety Precautions
• Be prepared for the occurrence of unexpected voltages at 
devices under test (e.g. defective devices). For example, 
capacitors may be dangerously charged.
• Make certain that the measurement cables are in flawless 
condition, e.g. no damage to insulation, no interruptions in 
cables or plugs etc.
• No measurements may be made with this instrument in 
electrical circuits with corona discharge (high-voltage).
• Special care is required when measurements are made in HF 
electrical circuits. Dangerous pulsating voltages may be 
present.
• Measurements under moist ambient conditions are not 
permitted.
• Be absolutely certain that the measuring ranges are not 
overloaded beyond their allowable capacities. Limit values are 
included in chapter 8, “Technical Data”, in the table entitled 
“Measuring Functions and Measuring Ranges” in the “Over-
load Capacity” column.
• The multimeter may only be operated with installed batteries or 
rechargeable batteries. Dangerous currents and voltages are 
otherwise not indicated, and the instrument may be damaged.
• The instrument may not be operated if the fuse cover or the 
battery compartment lid has been removed, or if its housing is 
open.
• The input for the current measuring range is equipped with a 
fuse link (exception: METRAHIT⏐B
ASE). 
Maximum permissible voltage for the measuring circuit (= rated 
voltage of the fuse) is 1000 V AC/DC.
Use specified fuses only (see page 59)! The fuse must have a 
breaking capacity of at least 30 kA.
Opening of Equipment / Repair
The equipment may be opened only by authorized service per-
sonnel to ensure the safe and correct operation of the equipment 
and to keep the warranty valid.
Even original spare parts may be installed only by authorized serv-
ice personnel.
In case the equipment was opened by unauthorized personnel, 
no warranty regarding personal safety, measurement accuracy, 
conformity with applicable safety measures or any consequential 
damage is granted by the manufacturer.
Repair and Parts Replacement
When the instrument is opened, voltage conducting parts may be 
exposed. The instrument must be disconnected from the measur-
ing circuit before the performance of repairs or the replacement of 
parts. If repair of a live open instrument is required, it may only be 
carried out by trained personnel who are familiar with the dangers 
involved.
Defects and Extraordinary Strains
If it may be assumed that the instrument can no longer be 
operated safely, it must be removed from service and secured 
against unintentional use.
Safe operation can no longer be relied upon:
• If the device demonstrates visible damage
• If the instrument no longer functions, or if malfunctioning 
occurs
• After long periods of storage under unfavorable conditions, 
e.g. humidity, dust or extreme temperature (see “Ambient Con-
ditions” on page 60)










