MS 8250B
Overview
This digital multimeter was designed with a view to comply with the safety require-
ments of standard IEC 61010-1. Complies with 600 V CAT III and 1000 V CAT II
measurement categories and Category 2 contamination requirements. Before us-
ing this instrument, please read this instruction manual and observe the relevant
safety precautions.
CAT IV: Measurements on low voltage power sources. For example, consumption
meters, input cabinets, primary surge protection devices
CAT III: Measurements inside buildings or plants. For example, fixed equipment,
distribution panel, cabling, bus bars, switches, surge protection distribution box,
etc.
CAT II: Measurements on circuits that are directly connected to low voltage cir-
cuits. For example, measurements on household appliances, portable devices and
similar equipment.
CAT I: Measurements on electric circuits that are not directly connected to mains.
Warning!
These operating instructions contain the information and warnings
required for the safe use and maintenance of the unit. Read and understand the
instructions for use before using the device. Failure to understand the instructions or
observe the warnings can result in serious personal injury or property damage. For
your safety, please use the probe cable included with the multimeter. Before use,
please check that your multimeter is intact and serviceable.
Safety Markings
Important warning Read the contents
of the instruction manual.
Risk of electric shock!
Grounding
Double grounding
(Contact protection class II)
Maintenance
In order to split the outer shell of the multimeter or remove the battery compartment
first unplug the probe cable. Before opening the multimeter, remove the battery and
check that there is no static electricity charge present to ensure that the multimeter’s
components are not damaged. Before opening the multimeter, you should be aware
that dangerous voltage may be present in some of the capacitors even if the device
is switched off. The calibration, maintenance and servicing of the multimeter should
only be performed by a specialist who is completely familiar with the operation of
the multimeter and the shock hazard involved. If not planning to use the multimeter
for an extended period of time, please remove the battery and avoid storing the unit
in excessively warm or humid environments. If necessary, replace the fuse with one
matching the parameters below:
F1: 6x30 mm, F 400 mA / 1000 V
F2: 6x30 mm, F10 A / 500 V
Do not use any abrasives or solvents on the device. Only use a damp cloth or mild
detergent for cleaning the unit.
During Use
• If the unit is used near strong electromagnetic interference, please note that the
multimeter’s operation can become unstable or it may indicate malfunction.
• Never exceed the safety limits which are specified in the instructions for each
measurement range.
• Never use the unit without its rear panel fully attached.
• Remove from circuit and discharge the high voltage capacitors before measuring
resistance, interruption, diodes or capacity.
• Be very careful when working with bare cables or bus bars.
• If any irregular operation is detected on the multimeter, immediately switch it off
and have it serviced.
• If the value to be measured is unknown, check the highest possible measurement
range on the multimeter, or whenever possible, select the automatic measure-
ment range mode.
• Before turning the limit selection switch, disconnect the probe cable from the
measurement circuit.
• Never perform resistance or interruption measurements on energized circuits.
• When performing measurements on TV sets or circuits with high AC, always re-
member that there might be high amplitude voltage on the test points, which can
damage the multimeter.
• If the voltage to be tested exceeds the effective value of 60 V DC or 30 V AC, work
carefully in order to avoid sustaining an electric shock.
• If the battery symbol appears on the display, the battery must be replaced im-
mediately. Low battery voltage may result in measurement errors, electric shock,
or even injury.
• Keep your fingers away from the connecting sockets.
• Do not use the multimeter in the presence of flammable gas, vapours or dust.
• Before each use, check the unit in order to ensure proper operation (e.g., using
a known voltage source).
• When measuring CAT IV voltage, the voltage may not exceed 600 V.
General description
This instrument features a 4 digit, 7-segment display. It can be used to measure
direct current, alternating current, DC voltage, AC voltage, resistance, frequency,
capacity, duty factor, diodes, and interruption. Features a contact free phase detec-
tor function. Capable of performing relative measurements, has background illumi-
nation, and automatically or manually switches measurement ranges. The reading
can be saved on the display. Switches off automatically. The multimeter can be
connected to a PC via a USB port.
Display symbols
Pushbuttons
FUNC
If more than one secondary function is available at any given dial
setting, this pushbutton can be used to toggle them. Each push of the
button shifts to the next function.
RANGE
Manual measurement range selection pushbutton: Pressing the
button once will cause the multimeter to enter manual measurement
range mode, and each addition press will shift it to the next measure-
ment range. Keeping the button pressed for 2 seconds will cause the
unit to return to automatic measurement range selection. Frequency
and capacity measurement only works with automatic measurement
range selection.
REL
Relative value. The current reading is stored at the moment the but-
ton is pressed, the “REL” symbol appears on the display and the
display is cleared. Afterwards, the reading appearing on the display
will be of a value relative to the previous one. Pressing the button
again or changing functions will cause the instrument to clear the
relative reading.
HOLD
Pressing this button will store the measured reading on the display.
Pressing the button again or changing functions will cause the instru-
ment to clear the data.
Hz%
Frequency/duty factor measurement toggle button. Each push of the
button shifts to the next function.
Digital multimeter
EN
low battery
negative input polarity
AC voltage/alternating current
DC voltage/direct current
diode test
interruption test
automatic measurement
range change
reading saved
REL
relative reading saved
%
duty factor measurement
mV, V
voltage measurement
µA, mA, A
current measurement
Ω, KΩ, MΩ
resistance measurement
Hz, KHz, MHz
frequency measurement
nF, µF
capacity measurement
PCLINK
computer connection
