Measurement category

Measurement category specifies the permissible applications of measuring and test equipment for electrical equipment and systems ( eg, voltage tester, multimeter, VDE test equipment) for use in the field of low voltage systems. The classification of the measurement category is defined by the IEC 61010-1 ( Safety requirements for electrical equipment for measurement, control, regulation and laboratory use ).

The category is for the safety of measurements of particular importance because low impedance circuits have higher short circuit currents and / or disturbances in the form of load transfer and other transients must be absorbed by the meter, without compromising the user from electrical shock, fire, sparking or explosion. Due to the low impedance of the public power supply network are on the house supply short-circuit currents is greatest. Inside the house system, the maximum short-circuit currents are reduced by the series resistance of the plant.

Technically compliance with the category is, inter alia, ensure safety of contact plugs and sockets, insulation, adequate clearances and creepage distances, strain relief and kink protection of cables and enough cable cross-sections.

The measurement category is featured on the meters with Roman numerals. If not specified, the instrument only for measurements of category 1 (CAT I) may be used.

The following categories and uses are defined in IEC 61010-1:

The categories are further divided into the voltage levels 300 V/600 V V/1000.