Mastech MY70, MY74, MY74B Operation Manual
MY70/74/74B
DI GI TA L M U LT I M E T E R
OP E R A T I O N MA N U A L
CAT III
600V
CONTENTS CONTENTS
1. General instructions
1.1 Safety information
1.1.1 Safety instructions
1.1.2 Safe working habits
1.1.3 Safety symbols
1.1.4 Safe maintenance habits
1.2 Input protection measures
2. Meter appearance description
2.1. Meter appearance
2.2 LCD display
2.3 Input socket
.......
.......................................................8
3. Operating guidance
3.1 General operation
3.1.1 Reading maintenance mode
3.2 Measuring guidance
3.2.1 Measuring AC and DC voltage
3.2.2 Measuring resistance
3.2.3 Testing diode
3.2.4 Audible continuity testing
3.2.5 Measuring capacitance (MY74,MY74B)
3.2.6 Transistor measuring
3.2.7 Measuring frequency (MY74,MY74B)
........................................1
..............................................1
............................................1
..........................................2
.................................................4
...................................5
...............................5
......................6
.............................................6
.................................................7
..........................................9
.............................................9
............................9
........................................9
..........................9
......................................10
.................................................11
...............................12
............12
.....................................13
...............13
3.2.8 Measuring temperature (MY74,MY74B)
3.2.9 Measuring current
4. Technical indicators
4.1. Comprehensive indicators
4.2. Accuracy indicators
4.2.1 DC voltage
4.2.2 AC voltage
4.2.3 Frequency (only for MY74,MY74B)
4.2.4 Resistance
4.2.5 Diode
4.2.6 Audible continuity
4.2.7 Transistor
4.2.8 Capacitance (only for MY74,MY74B)
4.2.9 Temperature (only for MY74,MY74B)
4.2.10 DC current
4.2.11 AC current
.............................................................18
5. Meter maintenance
5.1 General maintenance
5.2 Replace battery and fuse
5.3 Replacing Test L eads
5.4 Cleaning an d Dec ont ami nat ion
6. Accessories
............14
..........................................14
.......................................16
.............................16
........................................17
......................................................17
......................................................17
..................18
.....................................................18
...........................................19
.......................................................19
...............19
...............19
....................................................20
....................................................20
.........................................21
......................................21
................................21
....................................21
.................21
......................................................21
1. General instructions
The meter is design ed and manufactured accor ding to
saf ety requi rements of EN/UL /CSA 61010-1, 61010-2-030,
610 10-2-033 on electronic measuring instrument and
han d held digital multipurpose meter. The produc t meets
wit h the requirements of 600 V CAT III and pollution
deg ree 2.
• All saf ety gui delin es outl ined sh ould be f oll ow ed, I f th e
equi pment i s used in a m anner n ot spec ified b y the
manu factu rer, the p rotec tion pr ovide d by the eq uipme nt
may be i mpair ed.
• War ning sy mbols i n the man ual ale rt user s of pote ntial
dang erous s ituat ions.
• Prec autio ns are to p reven t the use r from da magin g the
inst rumen t or the te st obje ct.
WARNING:
The sp ec ial att en tion sh ou ld be pai d wh en usin g th e
mete r be cause t he i mprop er u sage ma y ca use ele ct ric
shoc k an d damag e th e meter . Th e safet y me asure s in
comm on s afety r eg ulati on s and ope ra ting in st ructi on
shou ld b e compl ie d with wh en u sing. I n or der to ma ke
full y us e of its fu nc tions a nd e nsure s af e opera ti ons
plea se c omply w it h the usa ge i n this se ct ion car ef ully.
1.1 Safety information
1.1.1 Safety instructions
* When using this meter, the user should comply with the
following standard safety procedures:
- The safety procedures to prevent electric shock
- The safety procedures to prevent wrong use
* To ensure your safety, please use the test probe provided
with the meter. Before use, please check and make sure
that it is intact.
1.1.2 Safe working habits
* If the meter is used near a source of significant electromagnetic
interference, meter readings will become unstable and have
large errors.
* Don’t use the meter or probe when it is broken.
* If you do not use the meter in accordance with the instructions,
safety functions provided by the meter may become invalid.
* When you work around the bare conductor or bus bar, you
should be extremely careful.
* Do not use the meter near explosive gas, vapor or dust.
* Measure known voltage with meter to verify that the meter is
working properly. If the meter is working abnormally, do not use.
Protective equipment may be damaged. If there is doubt,
the meter should be sent to repair.
* The meter should be used with correct input, function and
measuring range.
* When you can’t determine the size range of signal to be tested,
please switch the measuring range to the maximum position.
* Input value can’t exceed the input limit specified in each
measuring range to prevent damage to the meter.
* When the meter is connected to the circuit being measured,
do not touch the unused input end.
* When the voltage to be tested exceeds 60Vdc or 30Vac
effective value, please operate carefully to prevent electric
shock.
* When you measure with test probe, first connect the common
testing end of black test probe to the common testing end of
circuit to be tested, then connect red test leads to the test
circuit of the test probe to the test end of circuit to be tested.
When the measurement is completed, you should first remove
the red test probe, then remove the black common test probe.
01 02
* When use the test probe to measure, you should place your
fingers at the back of retaining ring.
* Before changing the measuring range, you must ensure that
the test probe is not connected to circuit to be tested.
* For all DC functions, including manual or automatic measuring
range, to avoid the risk of electric shock due to possible
incorrect readings, please use AC function to verify the
existence of any AC voltage. Then, select DC voltage
measuring range equal to or greater than the AC measuring
range.
* Before testing resistance, diode, capacitance measurement
or on-off states, you should first cut off power to the circuit
being tested, and discharge all high voltage capacitors.
* Don’t measure resistance or make on-off tests on a live circuit. .
* Before current measurement, you should firstly check the
meter's fuse. Before the meter is connected to the circuit
under testing,you should firstly power off the circuit to be
tested.
* When you make TV repairs or measure power conversion
circuits, you should note the high amplitude voltage pulse
of circuits being tested. The TV filter should be used to
weaken these pulses to avoid the meter damage.
* This meter uses a 9V 6F22 battery. The battery should be
properly installed in the meter’s battery compartment.
* When the battery indicator appears, the battery should be
replaced immediately. Low battery will cause meter reading
errors, and possibly result in electric shock or personal injury
* When you make type III voltage measurement, the voltage
should not exceed 600V; when you make type TV voltage
measurement, the voltage should not exceed 600V.
* When the meter shell (or part of shell) is removed, do not use
the meter.
1.1. 3 Safet y symbo ls
Symbols used on the meter surface and instructions:
Note -Impo rtant s afety i nform ation , refer t o the
inst ructi on manu al.
Caut ion, po ssibi lity of e lectr ic shoc k
Equi pment p rotec ted thr ougho ut by dou ble
insu latio n or rein force d insul ation .
Co nfo r ms to UL STD . 6 101 0 -1, 6 1 010 -2-0 30,
61 010 - 2-0 33; Ce rtif ied to C SA STD. C2 2.2
NO . 6101 0-1 , 6 101 0 -2- 030, 6 1010 -2- 033
Comp lies wi th Euro pean (E U) safe ty
stan dards
Eart h (grou nd) TERMI NAL
Dire ct curr ent
Alter natin g curre nt
MEASUREMENT CATEGORY III is applicable to test
CAT III
and measuring circuits connected to the distribution
part of the building's low-voltage MAINS installation.
03 04
1.1.4 Safe maintenance habits
* To open the meter shell or remove the battery cover, you
should first pull out the test probe.
* When performing meter maintenance, you should use
specified replacement parts.* Before opening the meter,
you should disconnect all power supplies and ensure that
you have no static electricity to avoid damaging the meter
components.
* Meter calibration, maintenance, repair and other operations
only can be performed by technicians who fully understand
the meter and electrical shock hazards.
* Before opening the meter, you should be aware that there
may be dangerous voltages remaining in some capacitances
in the meter even after powering off.
* If you find any abnormal phenomena on the meter, the meter
should be immediately turned off and repaired. Ensure that it
can not be used before passing inspection.
* When the meter is not used for a long time, please remove
the battery and avoid storing it in a high temperature and
humidity environment.
1.2 Input protection measures
* When making voltage measurements (not including 200mV
grade), the maximum input voltage is 600V DC or 600V AC.
(The maximum input voltage of 200mV grade is 250V AC or
equivalent RMS value voltage).
* When making frequency, resistance, on-off and diode
measurements, the maximum voltage is 250V AC or
equivalent RMS value voltage.
* When making capacitance, temperature, mA current, and
triode hFE measurements, the meter is protected through
a fuse (FF 400mA H 600V).
2. Meter appearance description
2.1. Meter appearance
2
5
1. LCD(liquid crystal display) 2. Mains Switch
3. HOLD Key 4. Rotary Switch 5. Input Socket
1
3
4
05 06
Loading...