General Technologies CT8022 Ergonomic Autorange Digital Multimeter - Manual (Page 2)

4.3.1 DC Voltage measurement
•
Set the FUNCTION SWITCH to “V” and the RANGE SWITCH to
“DC/
Ω” function.
• Connect the test leads across the source or load under
measurement.
• The measurement and polarity will be shown the LCD Display
when the probes are connected.
4.3.2 AC Voltage measurement
• Set the FUNCTION SWITCH to “V” and the RANGE SWITCH to
“AC/ ” function.
• Connect the test leads across the source or load under
measurement.
• The measurement will be shown on the LCD Display when the
probes are connected and current flows through the meter.
4.3.3 DC Current measurement
•
Set the FUNCTION SWITCH to “A” and the RANGE SWITCH to
“DC/
Ω” function.
• Connect the test leads in series with the source or circuit under
measurement.
• The measurement and polarity will be shown the LCD Display
when the probes are connected and current flows through the
meter.
4.3.4 AC Current measurement
•
Set the FUNCTION SWITCH to “A” and the RANGE SWITCH to
“AC/ ” function.
• Connect the test leads in series with the source or load under
measurement.
• The measurement will be shown on the LCD Display when the
probes are connected and current flows through the meter.
4.3.5 Resistance measurement
CAUTION: Maximum Input Voltage for this function is 250
Vrms for less than 10 Sec., do not exceed this
rating to avoid personal injuries or damage to the
instrument. Also ensure there is no power applied
to the component or circuit and all capacitors are
discharged.
• Set the FUNCTION SWITCH to “R” and the RANGE SWITCH to
“DC/
Ω” function.
• Connect the test leads across the component or circuit under
measurement.
• The range will adjust automatically for optimal readout, and the
measurement will be shown the LCD Display when the probe are
connected.
4.4 Other Functions
CAUTION: Maximum Input Voltage for this function is 250
Vrms for less than 10 Sec., do not exceed this
rating to avoid personal injuries or damage to the
instrument. Also ensure there is no power applied
to the diode.
4.4.1 Continuity Test
•
Set the FUNCTION SWITCH to “R” and the RANGE SWITCH to
“AC/ ” function.
• Connect the test leads across the circuit or component to test.
• Buzzer will sound if the circuit resistance is below 100Ω.
4.4.2 Logic Level Test
• Set the FUNCTION SWITCH to “TTL” and the RANGE SWITCH
to “DC/
Ω” function.
• Connect the test leads across the source or circuit under test.
• The logic level will be shown as “HI” or “LO” on the LCD display
according to the table below:
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General Technologies Corp.
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* The display will switch between HI and LO, but the response is
affected by the pulses frequency
4.4.3 Display Hold
A push button switch at the back of the unit is used to hold display
readings during measurements.
• Pressing the button holds the display reading, and “DH” appears
on the display.
• Pressing the button again resumes normal operation.
4.4.4 Auto Power OFF
The meter will turn off automatically to extend the battery life after
approx. 30 minutes without operating. To turn it on again, set
the FUNCTION SWITCH to the “OFF” position and then to the
desired range position.
5. MAINTENANCE
CAUTION: Before attempting battery removal or replacement,
disconnect test leads and remove the instrument
from any energized circuit to avoid shock hazard.
5.1 Battery Replacement
• When the battery needs replacement, the battery symbol will
appear in the lower left hand side of the LCD display.
• To replace the battery, remove the screw at the back Battery
Cover and replace with a new 9 V alkaline battery type NEDA
1604 or IEC6F22, observing the polarity as indicated at the back
of the case.
• Reinstall the battery cover and tighten the securing screw.
5.2 Fuse replacement
• To replace the internal fuse, turn the Fuse Cap counter clockwise,
to release the Fuse Cap assembly.
• Take out the blown fuse and replace with a type IEC60127-2 or
UL248-14 (5 x 20mm) fast acting fuse, rated at 400mA/250V.
• Replace the fuse cap, by inserting it in the meter body and turning
the Fuse Cap assembly clockwise, unitl it locks.
5.3 Cleaning
Periodically wipe the case with a soft damp cloth and mild household
cleanser. Do not use abrasives or solvents. Ensure that no water gets
inside the instrument to prevent possible shorts and damage.
6. WARRANTY
One year limited warranty, excluding batteries and fuses. For details
see Standard Warranty Information in our webpage or you may request
a printed copy.
Input Voltage TTL Logic Status Display
Above 2.0 V High HI
Below 0.8 V Low LO
0.8 to 2.0 V Undertermined -
Negative input (-V) Undertermined HI/LO or LO/HI*
Pulse Undertermined HI/LO or LO/HI*