GB Intsruments GMT-18A, Owner'S Manual

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3
4
Do not use this multimeter if you are unfamiliar with
electrical circuits and proper test procedures.
2.1 For Your Safety
1) WARNING! Use extreme caution when checking
electrical circuits.
2) WARNING! Do not stand in wet or damp work areas
when working with electricity. Wear rubber soled boots
or shoes.
3) WARNING! Do not apply more voltage or current
than the set range of the multimeter
will allow.
4) Do not touch the metal probes of the test leads when
making a measurement.
5) Replace worn test leads. Do not use test leads with
broken or tattered insulation.
6) Discharge a capacitor before measuring it.
7) Remove the test leads from the circuit being measured as
soon as the test is completed.
8) WARNING! Do not measure voltage when the
function/range switch is set on the resistance
(ohms) or the current (mA) settings. Never measure
current when the tester is set on the resistance range.
Never measure AC voltage when the tester is set on DC
voltage or DCmA. Setting the tester on the incorrect
function may burn out some of the internal circuitry and
may pose a safety hazard.
1) Set the function/range switch to the proper position
before making a measurement. When the voltage or
current is not known, it MUST be determined that the
capacity of the selected range will handle the amount of
voltage or current in the circuit (see #3 under “For Your
Safety”). Always start with the highest range in the
function. If the voltage applied falls within the range of a
lower setting, reset the function/range switch to the
appropriate setting for greatest accuracy of reading.
3.0 Operating Suggestions
2.0 Specifications
Ranges: 18 measuring ranges
DC Voltage: 2.5-50-250-1000 Volts
AC Voltage: 10-50-250-1000 Volts
DC Current: 10-250mA (milliamperes)
Resistance (Ohms): Rx10 (resistance indicated multiplied by 10)
Rx1K (resistance indicated multiplied by 1000)
10 Megohm max
Decibels: -20 to +62dB on AC voltage ranges
Accuracy: DC voltage, Amps = 4% full scale of range
AC voltage = 5% full scale of range
Resistance = 4% ARC of scale Length
Battery Test: 1 .5 volt and 9 volt batteries
Sensitivity: 10,000 ohms per volt DC and 4000 ohms per
volt AC
Operating Temperature: 18 deg. C to 25 deg. C = 64 deg. F to 77 deg. F
Function/Range Switch: 6 functions
15 positions
18 measuring ranges
Zero Ohms Adjustment Dial: Located on the left side of the housing, adjustment
dial is used to zero the needle indicator on the
ohms scale while shorting the test leads together.
Mechanical Zero Located directly below the center of the meter
Adjustment Screw: scale; adjust needle indicator to read zero
at the left side of the scale before taking
any measurement.
Mirrored Scale Plate: The mirror on the scale plate is used to line up the
needle with its reflection to improve the reading
accuracy by preventing parallax error.
Recessed Input Jacks: Negative (-) input jack for black test lead, positive
(+) input jack for red test lead.
Important:
Read this operators manual thoroughly before using this
multimeter. This manual is intended to provide basic
information regarding this multimeter and to describe
common test procedures which can be made with this unit.
Many types of appliance, machinery and other electrical
circuit measurements are not addressed in this manual and
should be handled by experienced service technicians.
WARNING!
Use extreme caution when using this multimeter.
Improper use of this meter can result in severe damage
to property, severe personal injury or death. Follow all
instructions and suggestions in this operators manual as
well as observing normal electrical safety precautions.
2.0 Specifications