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2. Explanation of symbols
The symbol with the exclamation mark in the triangle is used to highlight important information in these
operating instructions. Always read this information carefully.
The triangle containing a lightning symbol indicates the risk of an electric shock or of the impairment of the
electrical safety of the device.
The lightning symbol in the square permits current measurements on uninsulated, hazardous active con-
ductors and warns of the possible hazards. Personal protective equipment must be used.
The arrow symbol indicates special information and advice on how to use the product.
This product has been CE-tested and meets the relevant European guidelines
Protection class 2 (double or reinforced insulation, protective insulation)
CAT I
Measurement Category I: For measuring circuits of electrical and electronic equipment that is not directly
supplied with a mains voltage (e.g. battery-operated devices, safety extra-low voltage systems, and signal/
control voltages).
CAT II
Measurement Category II: For measuring electrical and electronic devices that are directly supplied with a
mains voltage via a mains plug. This category also includes all lower categories (e.g. CAT I for measuring
signal and control voltages).
CAT III Measurement Category III: For measuring circuits of installations in buildings (e.g. mains sockets or sub-
distributions). This category also includes all lower categories (e.g. CAT II for measuring electrical devices).
Measuring in CAT III is only permitted with test prods with a maximum free contact length of 4 mm or with
cover caps over the test prods.
CAT IV Measurement Category IV: For measuring at the origin of a low-voltage installation (e.g. mains distribution,
electricity provider’s transfer points to homes) and outdoors (e.g. when conducting tasks on underground
cables or overhead lines). This category also includes all lower categories. Measuring in CAT IV is only
permitted with test prods with a maximum free contact length of 4 mm or with cover caps over the test
prods.
Earth potential
