Velleman DVM851 User Manual
Page 5

DVM851
01.08.2012
5
6.
General description
The DVM851 is a battery-operated, hand-held 3 ½ digital multi-meter for measuring DC and AC
voltages, DC current and resistance. It also offers the possibility of executing continuity tests and of
testing diodes and transistors. The back light is optional.
Refer to the illustration on page 2 of this manual:
Display
3 ½ digits, 7 segments, LCD : 15mm high
Back light
When this button is pushed, the backlight will illuminate your display for approximately 5 seconds.
Rotary switch
This switch is used to select functions and desired ranges as well as to turn the meter on/off.
Hold button
Upon pushing this button, the display will retain the last reading and the "
the LCD until the button is pushed again.
"10A" jack
Insert the red test lead in this connector in order to measure a max. current of 10A.
"COM" jack
Insert the black (negative) test lead.
"V
Ω
mA" jack
Insert the red (positive) test lead in this connector to measure voltage, resistance and current
(except 10A).
7.
Overvoltage/installation category
DMMs are categorized depending on the risk and severity of transient overvoltage that might occur at the
point of test. Transients are short-lived bursts of energy induced in a system, e.g. caused by lightning
strike on a power line.
The existing categories according EN 61010-1 are:
CAT I
A CAT I-rated meter is suitable for measurements on protected electronic circuits that are not
directly connected to mains power, e.g. electronics circuits, control signals…
CAT II
A CAT II-rated meter is suitable for measurements in CAT I-environments and mono
appliances that are connected to the mains by means of a plug and circuits in a normal
domestic environment, provided that the circuit is at least 10m apart from a CAT III
apart from a CAT IV-environment. E.g. household appliances, portable too
CAT III
A CAT III-rated meter is suitable for measurements in CAT I- and CAT II
as for measurements on (fixed) mono- or poly-phased appliances which are at least 10m apart
from of a CAT IV-environment, and for measurements in or on distribution level equipment
(fuse boxes, lighting circuits, electric ovens).
CAT IV
A CAT IV-rated meter is suitable for measuring in CAT I-, CAT II- and CAT III
well as on the primary supply level.
Note that for all measurements on equipment for which the supply cables run outdoors (either
overhead or underground) a CAT IV meter must be used.
Warning:
This device was designed in accordance with EN 61010-1 installation category CAT II 600V. This implies
that certain restrictions in use apply that are related to voltages and voltage peaks which can occur
within the environment of use. Refer to the table above.
This device is only suitable for measurements up to 600V in CAT II
8.
Pollution degree
IEC 61010-1 specifies different types of pollution environments, for which different protective measures
are necessary to ensure safety. Harsher environments require more protection, and the protection
against the pollution which is to be found in a certain environment depends mainly on the ins
the enclosure properties. The pollution degree rating of the DVM indicates in which environment the
device may be used.
Pollution degree 1 No pollution or only dry, nonconductive pollution occurs. The pollution has no
influence. (only to be found in hermetically sealed enclosures)
Pollution degree 2 Only nonconductive pollution occurs. Occasionally, temporary conductivity caused by
©Velleman nv
easuring DC and AC
voltages, DC current and resistance. It also offers the possibility of executing continuity tests and of
When this button is pushed, the backlight will illuminate your display for approximately 5 seconds.
This switch is used to select functions and desired ranges as well as to turn the meter on/off.
"-symbol will remain on
Insert the red test lead in this connector in order to measure a max. current of 10A.
Insert the red (positive) test lead in this connector to measure voltage, resistance and current
nd severity of transient overvoltage that might occur at the
lived bursts of energy induced in a system, e.g. caused by lightning
ted meter is suitable for measurements on protected electronic circuits that are not
directly connected to mains power, e.g. electronics circuits, control signals…
environments and mono-phase
appliances that are connected to the mains by means of a plug and circuits in a normal
domestic environment, provided that the circuit is at least 10m apart from a CAT III- or 20m
environment. E.g. household appliances, portable tools…
and CAT II-environments, as well
phased appliances which are at least 10m apart
on distribution level equipment
and CAT III-environments as
quipment for which the supply cables run outdoors (either
1 installation category CAT II 600V. This implies
se apply that are related to voltages and voltage peaks which can occur
f pollution environments, for which different protective measures
are necessary to ensure safety. Harsher environments require more protection, and the protection
against the pollution which is to be found in a certain environment depends mainly on the insulation and
the enclosure properties. The pollution degree rating of the DVM indicates in which environment the
No pollution or only dry, nonconductive pollution occurs. The pollution has no
nd in hermetically sealed enclosures)
Only nonconductive pollution occurs. Occasionally, temporary conductivity caused by