Gardner Bender GMT-319, Owner'S Manual

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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
General
The first step in reading the analog scale is to
align the needle with the scale. This is
achieved by locating the mirror on the scale.
Line the needle up with its reflection. When
the reflection is hidden by the needle, the
needle is properly aligned.
Resistance (Ohms -
Ω
)
Use the top scale for reading the resistance.
If the meter is set to X1k, multiply the
resistance value by 1000
Ω .
DC Voltage (V DC)
Use the middle scale directly below the mirror.
Match the dial setting to the highest number on
the scale. If the setting does not match one of
the numbers, use a scale that can be easily
multiplied to give the setting (i.e. - for 1000V, use
the 10V scale and multiply the reading by 100).
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.
Decibel Gain (dB)
- see pg. 15
Use the scale marked dB to read decibels for
transistor gain. Use the chart at the right of
the scale for proper conversion.
3.2 Internal Battery Condition
Before making resistance or continuity tests,
check the condition of the internal battery. First
turn the function/range switch to a resistance
position. Short the test leads together and the
needle indicator should deflect to the right side
of the scale. Keep the test leads shorted
together while simultaneously turning the zero
ohms adjustment dial until the needle indicator
reads zero at the right side of the ohms
(green) scale. If the needle will not zero,
replace the battery with two new 1.5 volt AAA
size non-rechargeable batteries (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
DC
10
20
50
100
200
500
2K
5K
10K
6
8
1K
Resistance
(Ohms)
Scale
DC Voltage
& Milliamps
Scale
Common Markings
for both the AC & DC
Voltage Scales
AC Voltage Scale
dB Scale for Transistor
Gain Measurement
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GMT-319 manual 7.08.qxp 7/2/08 3:50 PM Page 8