DMM A960T User manual

1
DMM OPERATOR’S MANUAL
A960T
1. Overview
The DMM are characterized at slim size, portable, stable
performance and anti-dropping capacity. Using 3½ digits LCD
monitor with character 15mm high, they offer clear readings.
With overall circuitry design centering on large-scale IC A/D
converters in conjunction and over-load protection circuit, the
meters give excellent performance and exquisite making as a
handy utility instrument.
The meters can be used to measure DC & AC voltage, DC
current, resistance, positive diode voltage fall, hFE parameters
for transistor and Continuity.
2. Panel Layout
1LCD Display: 3½ digits,
character 15mm high
2Back Light Button Switch:
Press this button to switch on
back light If the dark
circumstance light makes the
reading difficulty when
measuring, the light will be
automatically turned off in 5
seconds. Press again to switch
it on again. If the battery is in
weak power, the light will be
dimmed.
3Data-hold Switch (HOLD)
4Power
5Rotary Switch: use this switch to select functions and
ranges
6“10A”Input Jack
7hFE test jack
8“COM”Input Jack
9“VΩmA” Input Jack
3. Safety Information
3-1 The meters are designed according to IEC-1010 concerning
electronic measuring instruments with an over-voltage
category (CAT II) and pollution 2.
3-2 Follow all safety and operating instructions to ensure that
the meter is used safely and is kept in good operating
condition.
3-3 safety symbols:
important safety information, refer to the operating manual.
Dangerous voltage may be presence.
Double insulation (protection Class II)
4. Special Cautions for Operation
4-1 The meters can be safe only according to standard
procedures when used in conjunctions with the supplied
test leads. To replace damaged test leads with only the
same model or same electric specifications.
4-2 To aveid risk of electric shock, do not use the meters
before the cover is in place.
4-3 The range switch should be at right position for the testing.
4-4 To avoid electric shock and damaging the instruments, the
input signals are forbidden to exceed the specified limits.
4-5 When measuring TV set or switched power, attention
should be paid to the possible pulses that may bring
destruction to the circuit.
4-6 Range switch position is forbidden to be changed at
random during measurement.
4-7 Take caution against shock in the course ot measuring
voltage higher than DC 60V & AC 30V.
4-8 Protection fuse should be replaced only with same type
and same specification.
5. GENERAL SPECIFICATIONS
5-1 Max Voltage between input terminal and Earth Ground: CAT
II 600V
5-2 Over-range Indication: display “1” or “-1” for the significant
digit.
5-3 Automatic display of negative polarity “ - ” .
5-4 Low Battery Indication: ‘ ’ displayed
5-5 Max LCD display: 1999 (31/2digits)
5-6 Fuse protection: F-200mA/250V (Ø5x20mm)
5-7 Power Supply: 9V battery, 6F22 or NEDA 1604
5-8 Operating Temp.: 0℃to 40℃(relative humidity <85%)
5-9 Storage Temp.: -10℃to 50℃((relative humidity
<85%)
5-10 Guaranteed precision Temp.: 23±5 ℃
(relative humidity <85%)
5-11 Dimension: 69x138x31mm (with holster)
5-12 Weight: approx: 170g (including battery)
6. Testing Specifications
Accuracy is specified for a period of year after calibration
and at 18℃to 28℃(64℉to 82℉) with relative humidity to
75%.
6-1 DC Voltage
Range
Resolution
Accuracy
200mV
0.1mV
±(0.5% of rdg + 2 digits)
2V
1mV
20V
10mV
200V
100mV
±(0.8% of rdg + 3 digits)
500V
1V
-- Input Impendence: 1MΩ
-- Overload protection: 250V for 200mV range, effective DC or
AC 600V for other ranges
6-2 AC Voltage
Range
Resolution
Accuracy
200V
0.1V
±(1.2% of rdg + 10 digits)
500V
1V
-- Frequency Range: 40 to 400Hz
-- Response: average, calibrated in rms of sine wave
6-3 DC Current
Range
Resolution
Accuracy
200μA
0.1μA
±(1.0% of rdg + 2 digits)
2mA
1μA
20mA
10μA
200mA
100μA
±(1.5% of rdg + 2 digits)
10A
10mA
±(3.0% of rdg + 5 digits)
-- Overload protection: F 200mA/250V fuse
Note:
10A range: not fused
6-4 Resistance
Range
Resolution
Accuracy
200Ω
0.1Ω
±(0.8% of rdg + 3 digits)
2KΩ
1Ω
20KΩ
10Ω
200KΩ
100Ω
2MΩ
1KΩ
±(1.0% of rdg + 3 digits)
-- Over-load protection: 250V effective value
6-5 Transistor hFE Test
Range
Test Range
Test Current / voltage
NPN & PNP
0-1000
Ib=10µA / Vce=3V
6-6 Diode Test
Range
Resolution
Function
1mV
Display: read approximate
forward voltage of diode
-- Over-load Protection: 250V effective value
-- Forward DC current: approximate 1mA
-- Reversed DC voltage: approximate 3.0V
6-7 Continuity
Range
Function
Built-in buzzer will sound if resistance is
less than 60Ω±30Ω
-- over-load protection: 250V effective value
--open circuit voltage: approximate 3.0V
6-8 Temperature
Range
Resolution
Accuracy
-20℃-750℃
1℃
±(1.0% of rdg + 2 digits)
-- over-load protection: 250V effective value
7. OPERATING INSTRUCTIONS
7-1 Attention before operation
7-1-1 Check 9V battery. If the battery voltage is less than 7V,
display will show “ ”, the battery should be replaced at
this time to ensure measuring precision.
7-1-2 Pay attention to the “ ” besides the input jack which
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shows that the input voltage or current should be within the
specified value.
7-1-3 The range switch should be positioned to desired range
for measurement before operation.
7-2 Measuring DC Voltage
7-2-1 Connect the black test lead to “COM” jack and the red to
“VΩmA” jack.
7-2-2 Set the rotary switch at the desired “V ” range position.
7-2-3 Connect test leads across the source or load under
measurement.
7-2-4 You can get reading from LCD. The polarity of the red lead
connection will be indicated along with the voltage value.
NOTE:
1. When the value scale to be measured is unknown
beforehand, set the range selector at the highest position.
2. When only the figure’1’ or ‘-1’ is displayed, it indicates
over-range situation and the higher range has to be
selected.
3. “ ” means you can’t input the voltage more than 600V, it’s
possible to show higher voltage, but it may destroy the
inner circuit or pose a shock.
4. Be cautious against shock when measuring high Voltage.
7-3 Measuring AC Voltage
7-3-1 Connect the black test lead to “COM” jack and the red to
“VΩmA” jack.
7-3-2 Set the rotary switch at the desired “V~” range position.
7-3-3 Connect test leads across the source or load under
measurement.
7-3-4 You can get reading from LCD.
NOTE:
1. When the value scale to be measured is unknown
beforehand, set the range selector at the highest position.
2. When only the figure ’1’ is displayed, it indicates over-range
situation and the higher range has to be selected.
3. “ ” means you can’t input the voltage more than 600V, it’s
possible to show higher voltage, but it may destroy the
inner circuit or pose a shock.
4. Be cautious against shock when measuring high Voltage.
7-4 Measuring DC Current
7-4-1 Connect the black test lead to “COM ”jack and the red to
the “VΩmA” jack for a maximum 200mA current , for a
maximum 10A current, move the red lead to the 10A jack.
7-4-2 Set the rotary switch at the desired “A ” range position.
7-4-3 Connect test leads in series with the load under
measurement.
7-4-4 You can get reading from LCD. The polarity of the red lead
connection will be indicated along with the current value.
NOTE:
1. When the value scale to be measured is unknown
beforehand, set the range selector at the highest position.
2. When only the figure’1’ or ‘-1’ is displayed, it indicates
over-range situation and the higher range has to be
selected.
3. “ ” means the socket mA’s maximum current is 200mA
and 10A’s maximum current is 10A, over current will
destroy the fuse. Since 10A is not fused, the measuring
time should be less than 1 second to prevent precision from
affecting by circuit heating.
7-5 Measuring Resistance
7-5-1 Connect the black test lead to “COM” jack and the red to
“VΩmA” jack.
7-5-2 Set the rotary switch at the desired “Ω”range position.
7-5-3 Connect test leads across the resistance under
measurement.
7-5-4 You can get reading from LCD.
NOTE:
1. When only the figure’1’ or ‘-1’ is displayed, it indicates
over-range situation and the higher range has to be
selected.
2. For measuring resistance above 1MΩ, the mete may take a
few seconds to get stable reading.
3. When the input is not connected, i.e. at open circuit, the
figure ‘1’ will be displayed for the over-range condition.
4. When checking in-circuit resistance, be sure the circuit
under test has all power removed and that all capacitors
have been discharged fully.
5. the value scale to be measured is unknown beforehand,
set the range selector at the highest position.
6. Under the Low Resistance Range, the Users are reques
ted to short the meter probes to get the resistance of test l
eads, which is needed to deduct from this measurement.
7-6 Transistor Testing
7-6-1 Set the rotary switch at “hFE” position.
7-6-2 Determine whether the transistor under testing is NPN or
PNP and locate the emitter, base and collector leads. Insert
the leads into proper holes of hFE socket on the front
panel.
7-6-3 Read the approximate hFE value at the testing condition
of base current Ib10uA and Vce 3V.
7-7 Diode Testing
7-7-1 Connect the black test lead to “COM” jack and the red to
“VΩmA ”jack. (the polarity of red lead is ‘+’)
7-7-2 Set the rotary switch at the “ ” range position.
7-7-3 Connect the red lead to the anode and the black lead to
the cathode of the diode under testing.
7-7-4 You can get a reading from LCD.
NOTE:
1. The meter will show approximate forward voltage drop of the
diode.
2. If the lead connections is reversed, only ‘1’ will be displayed.
7-8 Continuity Testing
7-8-1 Connect the black test lead to “COM” jack and the red to
“VΩmA” jack.
7-8-2 Set the rotary switch at the “ ” range position.
7-8-3 Connect test leads across two points of the circuit
under testing.
7-8-4 If continuity exists (i.e. resistance less than about
120Ω±30Ω), built-in buzzer will sound.
NOTE:
If the input open circuit, the figure “1” will be displayed.
7-9 Measuring Temperature
7-9-1 Set the rotary switch at the “℃” range position.
7-9-2 When measuring temperature ,Insert ‘K’ type
thermocouple probe (red one into “VΩmA” jack and black
one into “COM”jack)
7-9-3 Then put the ‘K’ type into the testing environment.
7-9-4 You can get a reading from LCD the testing temperature
after 10 seconds when the temperature become steady.
NOTE:
Don’t insert ‘K’ type,The LCD will sow the current
temperature of the environment.
8. Maintenance
8-1 Before attempting to remove the battery door or open the
case, be sure that test leads have been disconnected from
measurement circuit top avoid electric shock hazard.
8-2 To avoid electrical shock, remove test leads from
measurement circuits before replacing the fuse. For
protection against fire, replace fuses only with specified
ratings: F-200mA/250V fuse.
8-3 Your must replace the test leads if the lead is exposed, and
should adopt the leads with the same specifications as origin.
8-4 Use only moist fabric or small amount of detergent but not
chemical solution for cleaning.
8-5 do not use the meter before the back cover is properly
closed and screw secured. Upon any abnormality, stop
operation immediately and send the meter for maintenance.
9. Accessories
[1] Test Leads: electric rating 1000V 10A
[2] Battery: 9V, 6F22 or NEDA 1604
[3] Fuse: F-200mA/250V
[5] Operator’s Manual
[6] Holster
[7]K type