Internal Battery Condition; Dc Voltage Measurement - Gardner Bender GMT-312 Manuel D'utilisation

GMT-312 5-09 manual.qxp
adjustment screw clockwise or counterclock-
wise until the needle indicator is directly over
the three black zeros at the left end of the scale.
Analog Meter: Reading the Scale
5 4
5
200
10
100 20
120 180
40
1K
60
60 90
30
0
8
20
AC Voltage Scale
dB Scale for Transistor
Gain Measurement
General
The first step in reading the analog scale is to
align the needle with the scale.
Resistance (Ohms - Ω)
Use the top scale for reading the resistance.
If the meter is set to X1k, multiply the
resistance value by 1000Ω.
DC Voltage (V DC)
Use the middle scale. Match the dial setting to
the highest number on the scale.
AC Voltage (V AC)
Use the same numbers and procedures as
used for the DC voltage setting, but use the
scale directly below the numbers.
DC Milliamps
Use the same scale and procedure as used
for the DC voltage setting.
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5/21/09 3:04 PM
Decibel Gain (dB)
Use the scale marked dB to read decibels for
transistor gain. Use the chart at the right of
the scale for proper conversion.
Resistance

3.2 Internal Battery Condition

(Ohms)
2
Scale
1
Before making resistance or continuity tests,
240
check the condition of the internal battery. First
120
300
turn the function/range switch to the ohms
DC Voltage
150
Rx1K position. Short the test leads together
& Milliamps
and the needle indicator should deflect to the
Scale
right side of the scale. Keep the test leads
Common Markings shorted together while simultaneously turning
for both the AC & DC
the zero ohms adjustment dial until the needle
Voltage Scales
indicator reads zero at the right side of the
ohms (green) scale. If the needle will not zero,
replace the battery with a new 1.5 volt AA size
non-rechargeable battery (see Battery
Replacement ).

4. DC Voltage Measurement

1) Fully seat the test leads in the correct input
jacks, (-) black lead, (+) red lead.
2) Set the function/range switch to the
appropriate DC voltage range. If the voltage
is unknown, use the highest range. If the
voltage applied falls within the range of a
lower setting, reset the function/range switch
to the appropriate setting for greater accuracy.
3) If the polarity of the circuit to be tested is
known, touch the black test lead to the
neutral side. If the polarity is unknown, touch
the test leads to opposite sides of the circuit.
If the needle indicator deflects to the left of
the scale, reverse the test leads.
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- see pg. 15
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