Resistance Measurement; Dc Voltage; Ac Voltage - Mastech my68 Instruction Manual

NOTE: If you manually change the measurement range after
entering the Data Hold modes, the Meter exits this
mode.
2. To exit the manual ranging mode, press and hold down
RANGE RANGE
RANGE RANGE key for two seconds. The Meter returns to the
autorange mode and AUTO AUTO AUTO AUTO is displayed.
3.1.3 3.1.3 Battery 3.1.3 3.1.3 Battery Battery Saver Battery Saver Saver Saver
The Meter enters the "sleep mode" and blanks the display
if the Meter is on but not used for 30 minutes.
HOLD
Press the HOLD HOLD key or rotate the rotary switch to wake HOLD
the meter up.
To disable the Sleep mode, hold down the
while turning the meter on.
3.2 3.2 Measurement Measurement Functions Functions
3.2 Measurement 3.2 Measurement Functions Functions
3.2.1 AC and DC Voltage measurement
3.2.1 AC 3.2.1 3.2.1 AC AC and and DC and

DC Voltage

DC Voltage measurement Voltage measurement measurement
To To To To avoid avoid avoid avoid electrical electrical electrical electrical shock shock shock and/or shock
instrument, instrument, instrument, do instrument, do do not do not attempt not not attempt to to to to take attempt attempt
measurement that might
measurement measurement that measurement that that might might exceed might
750Vac 750Vac 750Vac 750Vac rms. rms. rms. rms.
To To To avoid To avoid avoid avoid electrical electrical electrical electrical shock shock shock shock and/or
instrument, instrument, instrument, instrument, do do not do do not apply not not apply apply apply more
750Vac 750Vac rms rms between between
750Vac 750Vac rms rms between between the
the the the the earth earth earth ground. earth ground. ground. ground.
The polarity of ac (alternating current) voltage varies over
time; the polarity of dc (direct current) voltage is constant.
The Meter's DC voltage ranges are 400.0mV, 4.000V,
40.00V, 400.0V and 1000V ； AC voltage ranges are
400.0mV , 4.000V, 40.00V, 400.0V and 750V.
(AC 400.0mV range only exists in manual ranging mode).
key
and/or and/or damage and/or damage damage damage to to to to the the the the
take take take any any any any voltage voltage voltage voltage
exceed 1000Vdc or or or or 1000Vdc
exceed exceed 1000Vdc 1000Vdc
and/or and/or and/or damage damage damage to to to to the damage the the the
more more more than than than than 1000Vdc 1000Vdc or or or or 1000Vdc 1000Vdc
the the common common terminal terminal and and
the common common terminal terminal and and
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To measure ac or dc voltage:
1. Set rotary switch to the DCV or ACV range.
2. Connect the black and red test leads to the COM and
V terminals respectively.
3. Connect the test leads to the circuit being measured
4. Read the displayed value. The polarity of red test lead
connection will be indicated when making a DCV
measurement.
NOTE:
NOTE: NOTE: NOTE:
¥ Unstable display may occur especially at 400mV range,
even though you do not put test leads into input terminals,
in this case, if an erroneous reading is suspected, short
the V terminal and the COM terminal, and make sure the
zero display.
¥ For better accuracy when measuring the dc offset of an
ac voltage, measure the ac voltage first. Note the ac
voltage range, then manually select a dc voltage range
equal to or higher than the ac range. This improves the
accuracy of the dc measurement by ensuring that the
input protection circuits are not activated.
3.2.2 Resistance measurement
3.2.2 3.2.2 Resistance 3.2.2

Resistance measurement

Resistance measurement measurement
To avoid To To To avoid avoid electrical avoid electrical electrical electrical shock shock and/or shock shock
instrument, instrument, disconnect disconnect
instrument, instrument, disconnect disconnect
discharge all discharge discharge discharge all all all high-voltage high-voltage high-voltage capacitors high-voltage
measuring resistance. measuring measuring measuring resistance. resistance. resistance.
The unit of resistance is the ohm (Ω). The Meter measures
resistance by sending a small current through the circuit.
Because this current flows through all possible paths
between the probes, an in-circuit resistance reading
represents the total resistance of all paths between the
probes.
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and/or and/or and/or damage damage damage to to to to the damage the the the
circuit circuit power power and and
circuit circuit power power and and
capacitors before capacitors capacitors before before before