VOLTCRAFT VC-330 Notice D'emploi page 31

Measurement category III for measurements in building installations
(e.g. power outlets and sub-distribution units). This category also
includes all lower categories (e.g. CAT II for measuring electrical
CAT III
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.
Earth potential
Symbol for the capacitance measuring range
Polarity markings (positive and negative) for direct current
measurement. The symbols show the direction of the current flow to
ensure the correct polarity when measuring.
Position marker for the conductor to ensure the correct current
measurement.
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