HT61 - HT62
EN - 3
1.2. DURING
USE
Please carefully read the following recommendations and instructions:
CAUTION
Failure to comply with the caution notes and/or instructions may damage
the instrument and/or its components or be a source of danger for the
operator.
Before activating the rotary switch, disconnect the test leads from the circuit being
measured.
When the instrument is connected to the circuit being measured, do not touch any
unused terminal.
Do not measure resistance in case external voltages are present; even if the
instrument is protected, an excessive voltage may cause malfunction.
While measuring, if the value or the sign of the quantity being measured remain
unchanged, check if the HOLD function is enabled.
1.3. AFTER
USE
When measurement is complete, set the rotary switch to OFF to switch off the
instrument.
If the instrument is not to be used for a long time, remove the batteries.
1.4. DEFINITION OF MEASUREMENT (OVERVOLTAGE) CATEGORY
Standard
“
IEC/EN61010-1: Safety requirements for electrical equipment for measurement,
control and laboratory use, Part 1: General requirements
”
, defines what measurement
category, commonly called overvoltage category, is. § 6.7.4: Measured circuits, reads:
(OMISSIS)
Circuits are divided into the following measurement categories:
Measurement Category IV
is for measurements performed at the source of the low-
voltage installation.
Examples are electricity meters and measurements on primary overcurrent protection
devices and ripple control units.
Measurement Category III
is for measurements performed on installations inside
buildings.
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 fixed installation.
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 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 standard requires that the transient withstand capability of
the equipment is made known to the user.
