VOLTCRAFT ET-200 Mode D'emploi page 38

CAT I Measurement Category I for measuring circuits of electrical and electronic equip-
ment that is not directly supplied with mains voltage (e.g. battery-operated devices,
protective extra-low voltage, signal and control voltages, etc.). Measuring operation
is permitted without cover caps on the probe tips.
CAT II
Measurement Category II for measuring electrical and electronic devices that are
directly supplied with mains voltage via a mains plug. This category also covers all
smaller categories (e.g. CAT I for measuring signal and control voltages). Measur-
ing operation is permitted without cover caps on the probe tips.
CAT III Measurement Category III for measuring circuits of installations in buildings (e.g.
electric sockets or sub-distributions). This category also covers all smaller catego-
ries (e.g. CAT II for measuring electronic devices). The measuring operation in CAT
III is permitted only with probe tips with a maximum free contact length of 4 mm or
with cover caps over the probe tips.
CAT IV
Measurement Category IV for measuring at the origin of the low-voltage installation
(e.g. main distribution, electricity provider's transfer points to homes, etc.) and out-
doors (e.g. tasks on earth line, overhead line, etc.). This category also contains all
lower categories. The measuring operation in CAT IV is permitted only with probe
tips with a maximum free contact length of 4 mm or with cover caps over the probe
tips.
Earth potential
Read operating instructions carefully.
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