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CaT II
Measuring category II for measurements at electrical and electronic devices con-
nected to the mains supply directly with a mains plug. This category also covers all
lower categories (e.g. CAT I for measuring signal and control voltages).
CaT III
Measuring category III for measuring in building installation (e.g. outlets or
sub-distribution). This category also covers all lower categories (e.g. CAT II for
measuring electronic devices). Measuring operation in CAT III is only permitted with
measuring prods with a maximum free contact length of 4 mm or with cover caps
above the measuring prods.
CaT IV
Measuring category Iv for measurements at the source of the low-voltage installa-
tion (e.g. main distribution, building handover points of the energy suppliers, etc.),
and outdoors (e.g. work at earthing cable, outdoor line, etc.). This category also
contains all lower categories. Measuring operation in CAT Iv is only permitted with
measuring prods with a maximum free contact length of 4 mm or with cover caps
above the measuring prods.
Earth potential
For safety and approval reasons (CE), unauthorised conversion and/or modification of the
device are not permitted.
Consult an expert when in doubt as to the operation, safety or the connection of the device.
Meters and accessories are not toys and have no place in the hands of children!
In commercial institutions, the accident prevention regulations of the Employer’s Liability Insur-
ance Association for Electrical Systems and Operating Materials are to be observed.
In schools, training centres, computer and self-help workshops, handling of meters must be
supervised by trained personnel in a responsible manner.
Ensure before each measurement that the Hold button “H” has not been pushed at the begin-
ning of the measurement (display with the Hold button pushed: “H”). If the Hold function is
activated before commencement of the measurement, no measured value is displayed!
The connected measuring lines are designed for the measuring category CAT III. The measur-
ing prods are applied with insulations to avoid accidental short circuits during the measure-
ment.
The voltage between the connection points of the meter and earth potential must not exceed
600 v DC/AC in CAT III.
