Cat I; Measurement Categories Cat; Premises In-House Installation; Proper Operating Conditions - Hameg HM5510 Handbuch

CAT I

The following remarks concern only the safety of the user.
Other aspects e.g. the maximum input voltage etc. are covered
in the Specifications section of this manual and are to be
observed as well.
This measuring instrument is destined for measurements in
circuits which are not connected in any way with the mains,
i.e. battery operated resp. galvanically isolated circuits. Direct
measurements (i.e. without galvanic isolation) in circuits of
measurement categories II, II, and IV are prohibited. Galvanic
isolation is ensured by an isolation transformer of Safety Class
II or a transducer such as a current probe of Safety Class II,
using any of these allows at least indirect measurements. In
any case the measurement category of the transducer must
be checked.

Measurement categories CAT

The measurement categories were created with respect to
the different kind of transients incurred in practice. Transients
are short, fast, and fast-rise changes of voltage or current,
they may be periodic or non-periodic. The amplitudes of
transients increase with decreasing distance from their
source.
CAT IV: Measurements at the source of a low voltage supply,
e.g. at electricity meters.
CAT III: Measurements inside a building, e.g. at distribution
sites, power switches, permanently installed mains
outlets, permanently mounted motors etc.
Overhead lines
CAT IV
Premises Permanently installed
In-house machinery, distribution sites,
installation power conductors, mains
outlets close to the CAT IV
installation
CAT III
I m p o r t a n t
CAT II: Measurements in circuits which are directly
connected with the low voltage supply, e.g. household
appliances, portable tools etc.
CAT I: Electronic instruments and circuits which contain
circuit breakers resp. fuses.

Proper operating conditions

Operation in the following environments: industry, business
and living quarters, small industry. The instruments are
destined for operation in dry, clean environments. They must
not be operated in the presence of excessive dust, humidity,
or chemical vapors neither in case of danger of explosion.
The maximum permissible ambient temperature during
operation is + 10 to + 40 degr. C. In storage or during transport
the temperature limits are: - 40 to + 70 degr. C. In case of
exposure to low temperature or if condensation is to be
suspected the instrument must be left to stabilize for at least
2 hrs. prior to operation.
In principle the instrument may be used in any position,
however, sufficient ventilation must be ensured. Operation for
extended periods of time require the horizontal or tilted (hand-
le) position.
Do not block the ventilation holes.
Nominal specifications are valid after 30 minutes warm-up at
23 degr. C. Specifications without tolerances are typical values
taken of average production units.
STOP
Mains outlets for
household appliances,
portable tools, PC,
refrigerator etc.
h i n t s
CAT II
Subject to change without notice
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