Iec Measurement Category Definitions - Keysight N2894A User Manual

IEC Measurement Category Definitions

Definitions and Examples (Clause 6.5.2).
Measurement Category I (CAT I)
Measurement category I is for measurements performed on circuits not directly
connected to a mains supply.
Example
Measurements in circuits not derived from a mains supply and specially protected
(internal) circuits derived from a mains supply. In the latter case, transient stresses
are variable. For that reason, it is required that the transient withstand capability of
the equipment is made known to the user.
Measurement Category II (CAT II)
Measurement category II is for measurements performed on circuits directly con-
nected to the low voltage installation.
Example
Household appliances, portable tools, and similar equipment.
Measurement Category III (CAT III)
Measurement category III is for measurements performed in the building installa-
tion.
Example
Measurements on distribution boards, circuit breakers, wiring including cables,
bus-bars, junction boxes, switches, socket-outlets in the fixed installation and
equipment for industrial use like, for example, stationary motors with permanent
connections to the fixed installation.
Measurement Category IV (CAT IV)
Measurement category IV is for measurements performed at the source of the
low-voltage installation.
Example
Electricity meters and measurements on primary over-current protection devices
and ripple control units.
Keysight N2870A-Series and N2894A Passive Probes User's Guide
IEC Measurement Category Definitions
33