Hold-Button; Connection And Operation; Range-Button; Alternating And Direct Current Measurement - Bosch MMD 302 Manual Original

en 20 | MMD 302 | General Information
3.5.5

HOLD-button

R
The current display is "frozen" when this button is
pressed. This is indicated by the appearance of the
H symbol.
R
Press the HOLD-button again in order to cancel the
HOLD function.
i
The automatic appliance-shut-off function is deacti-
vated during HOLD mode.
3.5.6 PWR RST-button
The MMD 302 switches off automatically approx.
30 minutes after the last button or the measurement-
mode switch is actuated.
i
The unit is switched back on again by pressing the
PWR RST-button.
3.5.7

RANGE-button

R
This RANGE-button allows you to set a certain mea-
surement range. In order to return to the automatic
measurement-range changeover function, press the
RANGE-button (approx. 2 seconds) until AUTO ap-
pears in the display.
R
You can exit the REL - and MIN./MAX. mode by press-
ing the RANGE-button for approx. 2 seconds.
3.5.8 Measurement-mode switch
Selecting the desired measurement mode and switch-
ing off the appliance.
place Function / Meaning
OFF Switch position when the appliance is switched off
V~ Measurement of alternating voltage
V= Measurement of direct voltage
Continuity test or resistance measurement
(changeover by means of the blue function button)
Capacitance measurement or diode test (change-
over by means of the blue function button)
ADP Hz Hz = frequency measurement
ADP = no function
4 mA Measurement of direct and alternating current up
to 4 mA (changeover between direct and alternat-
ing current by means of the blue function button)
40 mA Measurement of direct and alternating current up to
40 mA (change-over between direct and alternating
current by means of the blue function button)
400 mA Measurement of direct and alternating current up to
400 mA (changeover between direct and alternating
current by means of the blue function button)
A Measurement of direct and alternating current up
to 10 A (changeover between direct and alternat-
ing current by means of the blue function button)
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4.

Connection and operation

The following applies to all measuring modes and
ranges:
!
The correct measuring mode must first be selected
in order to prevent damage to the measuring appli-
ance. Only then may the measuring cables be con-
nected to the measuring object!
1. Connect the black measuring cable to the earth
input (fig. 1, pos. 11).
2. A pulsating buzzer warning signal is emitted if a
measuring range is exceeded. In addition, 4000
appears in the display, and the highest value digit
flashes.
3. Negative polarity of the input value is identified by a
"–" before the measured value.
4.1 Alternating and direct current
measurement
1. Connect the red measuring cable to the test input
for voltage measurement (fig. 1, pos. 12).
2. Turn the measurement-mode switch (fig. 1, pos.
8) to the desired position for alternating or direct
voltage. In the display, AC is shown for alternating
voltage and DC for direct voltage.
3. Connect the test probes parallel to the measure-
ment object.
4.2 Acoustic continuity test and
resistance measurement
1. Connect measuring cable to test input for
resistance measurement (fig. 1, pos. 12).
2. Turn measurement-mode switch (fig. 1, pos. 8) to
the position.
3. You can switch from acoustic continuity test to resis-
tance measurement by means of the blue function
button (fig. 1, pos. 2). In the display,
acoustic continuity test and Ω for resistance mea-
surement.
!
Switch off the power supply to the measurement
object and discharge the condensers (capacitors),
as the MMD 302 could otherwise be dama- ged!
4. Connect the test probes parallel to the
measurement object.
5. A buzzing sound occurs in the acoustic continuity
test mode for resistance values less than 35 Ω.
is shown for
Robert Bosch GmbH