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CAT III Overvoltage category IV for measuring at the source of the low-voltage installation (e.g.
main distribution, house-transfer points of energy providers, etc.) This category also con-
tains all lower categories.
Ground potential
For safety and licensing reasons (CE), unauthorised conversion and/or modification of the device is not
permitted.
Consult an expert when in doubt as to the operation, the safety or the connection of the device.
meters and accessories are not toys and have no place in the hands of children.
On industrial sites, the accident prevention regulations of the association of the industrial workers’
society for electrical equipment and utilities must be followed.
In schools, training centres, computer and self-help workshops, handling of meters must be supervised
by trained personnel in a responsible manner.
Before measuring voltages, always make sure that the meter is not set to a measuring range for cur-
rents.
The voltage between the connection points of the measuring device and the ground potential must not
exceed 1,000 V DC/AC in CAT IV III or 600 V CAT IV.
The measuring prods have to be removed from the measured object every time the measuring range is
changed.
Be especially careful when dealing with voltages higher than 25V AC or 35 V DC. Even at these voltages
it is possible to receive a fatal electric shock if you touch electrical conductors.
Check the measuring device and its measuring lines for damage before each measurement. Never carry
out any measurements if the protecting insulation is defective (torn, ripped off etc.)
To avoid an electric shock, make sure not to touch the connections/measuring points to be measured
neither directly nor indirectly during measurement. During measuring, do not grip beyond the grip range
markings (which you can feel) present on the test probes.
Do not use the multimeter just before, during or just after a thunderstorm (lightning! / high-energy over-
voltage!). Please make sure that your hands, your shoes, your clothing, the floor, switches and switching
components are dry.
Avoid an operation near:
- strong magnetic or electromagnetic fields
- transmitter aerials or HF generators,
This could affect the measurement.
