IV
User Manual
Measurement Category
Measurement Categories
The oscilloscopes can make measurements in measurement category I.
WARNING
This oscilloscope can only be used for measurements within its specified
measurement categories.
Measurement Category Definitions
Measurement category I is for measurements performed on circuits not directly connected
to MAINS. Examples are measurements on circuits not derived from MAINS, and
specially protected (internal) MAINS derived circuits. In the latter case, transient stresses
are variable; for that reason, the transient withstand capability of the equipment is made
known to the user.
Measurement category II is for measurements performed on circuits directly connected to
the low voltage installation. Examples are measurements on household appliances,
portable tools and similar equipment.
Measurement category III is for measurements performed in the building installation.
Examples are 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 and some other equipment, for example. Stationary motors
with permanent connection to the fixed installation.
Measurement category IV is for measurements performed at the source of the low-voltage
installation. Examples are electricity meters and measurements on primary over current
protection devices and ripple control units.
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