Mastech MS8250D User Manual

MS8250D

DUAL DISPLAY
DIGITA L M U LT I M E T E R
User’s Manual

Warning

01 02

1. Safety Information

Use caut io n an d follow all safety guidelines to
preven t el ec tric shock or damage to the meter.
Please r ea dy c arefully all instructions b ef or e use.

Instru me nt m eets GB/T 13 978-92 concerning digital
multim et er s tandards, along with G4B793 .1 -1 995
(IEC-6 10 10 -1,IEC-61010-2-032)sa fe ty s tandards or
electr ic al m easuring instruments with a n ov er-voltage
catego ry o f CAT IV 600V,C AT III 1000V.
Follow a ll s afety instructions to ensure sa fe u se a nd long
life of th e in st rument.

1.1 Prepara tion

1.1.1 Wh en u si ng the meter, follow all standar d sa fe ty
guidel in es :

- For univ er sa l protection again electric s ho ck .

- To preven t th e mi suse of the instrument.

1.1.2 Ch ec k th e meter for damage during trans it .

1.1.3 Test leads must be i n go od c ondition.Check the
insula ti on a nd tips before use.

1.1.4 Sa fe ty c an only be guaranteed with lead s pr ov ided.
If leads n ee d to b e replaced, they must be replac ed
with lea ds o f sa me electrical specificati on s.

1.2 Using the M eter

1.2.1 Alw ay s se t the meter to the proper functio n an d
range fi rs t.

1.2.2 Ne ve r ex ceed protection limits indi ca te d for each
measur em en t.

1.2.3 Ke ep f in gers behind the probe barrier s wh ile
measur in g.

1.2.4 Alw ay s be c areful when working with volt ag es
above 60 V DC o r 30 V AC RMS.

1.2.5 Ne ve r me asure voltages that might exc ee d 60 0V
DC/AC ab ov e ea rth ground.

1.2.6 In m an ua l range, if the circuit value is un kn ow n,
start th e me te r at the maximum range and then
adjust a cc or dingly.

1.2.7 Re mo ve t he leads from the circuit first b ef or e
switch in g be tween functions.

1.2.8 Do n ot p ow er on circuit while measuring r es istance,
capaci ta nc e, diodes and continuity.

1.2.9 Ne ve r co nnect the meter ’s l ea ds across a voltage
source w hi le t he rotary switch is in the resist an ce ,
capaci ta nc e, diode or continuity mode.

1.2.10 D o no t me asure capacitance before ca pa citors
are disc ha rg ed.

1.2.11 Do not operate t he m et er near explosive gas,
vapor or d us t.

1.2.12 S to p us ing the meter if any abnormalit y is o bs erved.

1.2.13 D o no t us e the meter unless the battery co ve r is
secure ly f as tened to the meter.

1.2.14 Avoid direct e xp os ure to sunlight to ensure
extend ed l if e of the meter.

03 04

1.3 Safety Sy mbols

1.4 Mainten ance

1.4.1 To avoid electri c sh oc k or personal injury, repairs/
servic in g no t covered in this manual should b e
perfor me d on ly by qualified personnel.

1.4.2 Re mo ve t est leads from any circuit befo re o pe ning
batter y co ve r.

1.4.3 To avoid false rea di ng s that may become
danger ou s, r eplace the battery as soon as the
ymbol ap pe ar s.

1.4.4 Cl ea n th e meter using a damp cloth and mild
deterg en t on ly; do not use abrasives or chemi ca l
solven ts .

1.4.5 Alw ay s mo ve rotary switch to OFF when not us in g
the mete r.

1.4.6 If m et er i s not going to be used for an extende d
period o f ti me , remove battery to prevent damag e
to the met er.

2. Description

-The MS8 25 0D i s a portable, hand-held yet pro fe ss ional
meter th at f ea tures True RMS measurement dis pl ay,
AC/DC cur re nt , AC/DC voltage, Frequency,
Capaci ta nc e, Resistance, Continuity, Duty Ratio, D io de
Testing a nd a U SB adapter for recording read in gs o n a
PC. This Meter is easy t o us e ev en with one hand, s
uitabl e fo r pr ofessional users or amateur s, a nd i deal for
school o r ho me u se.

- Both aut o an d ma nual range.

- Displa y ho ld

- True RMS fo r AC vo lt age/current measurement s

- Relati ve m ea surement

- Maximu m me as urement

- Minimu m me as urement

- Displa y fr eq uency when measuring AC voltag e/ current

- Automat ic P ow er Off

Import an t sa fety information, please re fe r
to user’s manual

Cautio n wh en testing on live conductors

Double i ns ulation protection (categor y II )

This met er h as m et IEC61010-1 standard
with an ov er vo ltage category (600V CAT IV)
and poll ut ion degree 2.

CAT IV

Double i ns ulation protection (categor y II )

Ground

2.1 Part Name

(1)
(2)
(3)
(4)
(5)
(6)
(7)

USB inte rf ac e
NCV dete ct io n indicator
LCD disp la y
Functi on b ut tons
Rotary s wi tc h
Input so ck et s
NCV dete ct io n sensor

Compli es w ith U.S. and Canadian safety
standa rd s

05 0 6

2.2 2 Buttons /Input jack desc ription

HOLD: ke ep c ur rent reading on the display
FUNC: sw it ch b etween functions or AC/DC meas ur ement
RANGE: s wi tc h between auto/manual range s
REL: dis pl ay r elative measurement
MAX/MI N: s wi tch between max/min measure me nt d isplay
:turn on /o ff backl ig ht
OFF:Po we r off posi ti on

:input j ac k fo r voltage, resistance, capa ci ta nce,
diode, c on ti nuity, fr eq uency and duty cycle
measur em en t

:commo n te rm inal

: input ja ck f or c urrent measurement (<660m A)

:input j ac k fo r current measurement (<10A )

COM

μAmA

10A

V

Hz%

2.3 LCD displ ay

1

2

4

5

6

3

7

07 0 8

Altern at in g current
Direct c ur re nt
Diode
Contin ui ty
Auto ran ge

Maximu m di sp lay
Minimu m di sp lay

Low batt er y
Percen ta ge ( duty cycle)
Hertz, k il oh ertz (frequency)
Milliv ol ts , volts (voltage)
Micro am ps , mi lliamps, amps (current)
Nanofarad, microfarad, millifarad (capacitance)
Ohms, ki la oh ms, megaohms

Relati ve d isplay

AUTO

MAX

MIN

%

Hz, kHz

mV, V

REL

Ω, kΩ, MΩ

nF, μF, mF

μA, mA, A

3. Specifications

Instru me nt s hould be calibrated annuall y at 1 8°C~28°C
and rela ti ve h umidity of <75%.

NCV

Non-co nt ac t voltage detection

USB inte rf ac e active

Auto pow er o ff

3.1 General S pecifications

3.1.1 Aut o an d ma nual range

3.1.2 Fu ll r an ge overload protection

3.1.3 Ma x. v ol tage between terminal and
ground : 60 0V D C or AC rms

3.1.4 Op er at ing altitude: 2000m max.

3.1.5 Di sp la y: 6600 count LCD

3.1.6 Po la ri ty indication: automatica ll y di splays “-”

3.1.7 Ov er r an ge indication: “OL” or “-OL”

3.1.8 Sa mp le r ate: approx. 0.4s/analog ba r
graph: a pp ro x. 0.04s
except f or c ur rent measurement: approx.
1s/bar g ra ph : 0.1s

3.1.9 Un it d is play: functions and unit powe r

3.1.10 Au to p ow er off t im e: a pprox. 15 min.

3.1.11 Power supply : 9V b at tery

3.1.12 L ow b at tery indication: display sh ow s“ ”

3.1.13 Temp. coefficient: less tha n 0. 1 x accuracy/°C

3.1.14 O pe ra ting temperature: 0~40°C

3.1.15 S to ra ge temperature: -10~50°C

3.1.16 D im en sions: 180x86x52mm

3.1.17 Weight: app ro x. 2 50g (without battery)

09 1 0

3.2 Technical Indicators

3.2.1 Tru e RM S ch aracteristics

3.2.1. 1 Fo r no n-sinusoidal signal measu re ment, the
Meter pr ov id es more accurate measuremen t th an
the trad it io nal averaging method.

3.2.1. 2 If i n AC cu rrent mode, the Meter may displ ay a
random r ea di ng between 1 and 50 when the input
is not activ e. This will n ot a ffect th e ac cu racy of
measur em en t.

3.2.1. 3 Tru e RM S requires a minimum input leve l, AC
curren t or v ol tage should be 2%~100% of the
maximu m le ve l.

3.2.2 DC Voltage

Resolu ti on

0.1mV

Accura cy

±(0.8% reading + 3 digits)of

660mV

0.001V

0.01V

0.1V

6.6V
66V

600V

±(0.5% reading + 5 digits)of

Range

- Input im pe da nce: 10M

- Overlo ad p ro tection: 660mV range: 250V DC o r AC rm s.

6.6V-10 00 V ra nges: 1000V DC or 1000V AC rms.

- Max. inp ut v ol tage: 1000V DC

Ω

0.1V1000V

3.2.3 AC Vol ta ge

Resolu ti on

0.1mV

Accura cy

±(1.5% reading + 5 digits)

660mV

0.001V

0.01V

0.1V

6.6V
66V

600V

±(1.2% reading + 5 digits)

Range

±(1.5% reading + 5 digits)

- Input im pe da nce: 10MΩ

- Overlo ad p ro tection: 660mV range: 250V DC o r AC rm s.

6.6V-10 00 V ra nges: 1000V DC or 1000V AC rms.

- Max. inp ut v ol tage: 1000V DC

- Freque nc y re sponse: 50 ~ 60Hz

- Respon se : Tru e RMS

0.1V

1000V

±(1.5% reading + 5 digits)

3.2.4 Re si st ance

Resolu ti on

0.1Ω

Accura cy

660Ω

0.001kΩ

0.01kΩ

0.1kΩ

6.6kΩ
66kΩ

660kΩ

6.6MΩ

±(0.8% reading + 5 digits)

Range

±(1.5% reading + 5 digits)

- Open cir cu it v oltage: approx. 0.4V

- Overlo ad p ro tection: 250V DC or AC rms.

66MΩ 0.1MΩ

0.001MkΩ

11 12

3.2.5 Ca pa ci tance

Resolu ti on

0.001nF

Accura cy

6.6nF

0.01nF

0.01µF

0.01µF

66nF

66µF

660µF

±(4.0% reading + 5 digits)

Range

- Overlo ad p ro tection: 250V DC or AC (RMS)

0.1µF

0.1nF660nF

6.6µF

6.6mF
66mF

0.001mF

0.01mF

±(3.0% reading + 3 digits)

±(4.0% reading + 5 digits)

3.2.6 Di od e Test

Resolu ti on Functi on

Range

Displa y ap proximate diode
forwar d vo lt age value

0.001V

- Forwar d DC c ur rent: approx. 1mA

- Revers e DC v ol tage: approx. 3.3V

- Overlo ad p ro tection: 250V DC or AC rms.

3.2.7 Ci rc ui t Continuity Test

Resolu ti on Functi on

Range

If the res is ta nce of circuit to be
measur ed i s le ss than 30Ω, the
meter' s bu il t-in buzzer will
sound.

0.1Ω

- Open cir cu it v oltage is about 1.2V

- Overlo ad p ro tection: 250V DC or AC (RMS)

3.2.8 Fr eq ue ncy

3.2.8. 1 In V m od e:

Resolu ti on

Accura cy

66Hz

±(1.5% reading + 5 digits)

Range

660Hz

10kHz

0.01Hz

0.1Hz

0.001kHz

0.01kHz

6.6kHz

- Freque nc y ra nge:10Hz~10kHz

- Input vo lt ag e range: >0.2V AC(rms)(as meas ur ed
freque nc y in creases,voltage will also i nc re ase)

3.2.8. 2 Pa ss H z grade:

Resolu ti on

Accura cy

66Hz

±(1.5% reading + 5 digits)

Range

660Hz

6.6kHz

660kHz

6.6MHz
66MHz

0.01Hz

0.1Hz

0.001kHz

0.01kHz

0.1kHz
1kHz

10kHz

66kHz

- Overlo ad p ro tection:250V DC or AC rms.

- Measur em en t signal: 3Vpp AC

3.2.8. 3 Du ty R atio

Resolu ti on

Accura cy

1-99%

Range

0.1% ±2.0%

13 14

3.2.9 DC C ur re nt

Resolu ti on

Accura cy

660µA

±(1.0% reading + 5 digits)

Range

66mA

10A

0.1µA
1µA

10µA

10mA

±(2.0% reading + 5 digits)

6600µA

660mA

100µA

- Overlo ad p ro tection:
µA/mA jac k: F 6 00 mA/1000V. A jack: F10A/600 V.

- When mea su ri ng current larger than 5A, do not c on ti nue
measur em en t for greater than 10s. Wa it 1 m in. after
measur em en t before resuming.

3.2.10 AC Current

Resolu ti on

Accura cy

660µA

±(1.5% reading + 5 digits)

Range

66mA

10A

0.1µA
1µA

10µA

10mA

±(3.0% reading + 5 digits)

6600µA

660mA

100µA

- Overlo ad p ro tection:
µA/mA jac k: F 6 00 mA/1000V. A jack: F10A/600 V.

- Freque nc y re sponse:50 ~ 60Hz

- Respon se : Tru e RMS

- When mea su ri ng current larger than 5A, do not c on ti nue
measur em en t for greater than 10s. Wa it 1 min.after
measur em en t before resuming.

4. Using the Meter

4.1 Data Hold

4.1.1 Du ri ng m easurement, if you want to keep t he
readin g on t he d isplay, pre ss“HOLD”and the
readin g wi ll b e held.

4.1.2 Pr es s“ HOLD”again to release the hol d.

4.2 Manual Ra nge

4.2.1 In v ol ta ge, current, resistance, ca pa ci tance, and
freque nc y mo des, the default range is auto.

4.2.2 Pr es s“ RANGE”to switch to manual ran ge .E ach
press of t he b ut ton increases the range, and re tu rn s
to the low es t ra nge when pressed in the largest
range.

4.2.3 Ho ld d ow n“RANGE”for 1 second to retur n to a ut o
range.

4.2.4 Wh en i n Ma x/Min modes, pressing“RAN GE ”t o
return t o no rm al measurement.

Note:

Freque nc y ca nnot be set to manual range.

4.3 Relativ e Mode

4.3 1 Press“ RE L” to enter relative mode.The me te r st ores
the meas ur ed v alue when the button was presse d
and comp ar es i t to the currently measured val ue
(rel = cur re nt r eading - stored reading).

.

4.4 Maximum /Minimum Mode

4.4.1 Pr es s M AX /MIN in any range to show the maximu m
value re co rd ed; press“MAX/MIN”again t o sh ow t he
minimu m va lu e recorded; press“MAX/MIN ”a t hi rd
time to re tu rn t he display to normal.

“ ”

15 1 6

4.4.1 In v ol ta ge and current modes, press“F UN C” to
switch b et we en AC and DC modes.

4.4.1 In t he m ul ti-function position, pre ss “F UNC”to switch
betwee n re si stance, diode and continuit y mo de s.

4.5 Functio n Switch

4.6 Backlig ht

4.7 Automatic 9ower-off

4.6.1 Pr es s “ ” ke y, turn on or o ff backlig ht .

4.7.1 If t he m et er is not used for 30 minutes, the me te r
will aut om at ically turn itself off to save battery power.

4.7.2 To turn the meter ba ck o n, p ress any button.

4.7.3 Ho ld in g FUNC when tur ni ng on the meter will
disabl e au to p ower off .

“ ”

4.9 NCV (Non- Contact Voltage det ection)

4.8 USB Commu nication

4.8.1

4.8.2

4.8.3

Instal l th e in cluded software and USB drive r

( See PC CD- RO M so ftware user ’s gui de ) on a P C.

Use the in cl ud ed USB cable to connect the meter

to the PC; the symbol a pp ears on the display.

Open the i ns ta lled software and the meter wil l be gin

sendin g th e me asured data to the software.

4.9.1 Mo ve t he r otary switch to the NCV positio n.

4.9.2 Mo ve t he N CV sensor (top of the meter) towa rd t he
object t o be t es ted. If the sensor detects voltag e
greate r th an 110VAC (rms), the NCV ind ic at or will
flash an d th e me ter will beep.

Note:

1.Even w it ho ut indication, voltage may st il l ex ist. Do not
solely r el y on N CV detection to determine in vo lt ag e
exists . De te ction may be affected by socket design,
insula ti on t hickness or other factors.

2.NCV in di ca tor may go off w hen measuring voltage due
to the pre se nc e of induced voltage.

3.Inte rf er ence sources may accidental ly t ri gger NCV
detect or.

4.10 DC/ AC Voltage

Voltage i s th e potential difference between two points .
The pola ri ty o f AC voltage changes over time whe re D C
voltag e po larity does not.
DC volta ge r an ges: 660.0mV、6.600V、 .00V、 0. 0V.
1000V AC vo lt age ranges: 660mV、6.600V、66.00V、

660.0V. 1000V. 660mV ra ng e ca n only be entered through
manual r an ge.
Measur in g DC/AC voltage:

4.10.1 M ov e th e rotary switch to the position .

4.10.2 C on ne ct the red test lead to the V jack and th e
black le ad t o th e COM jack.

4.10.3 C on ne ct the leads in parallel with the c ir cuit under
test.

4.10.4 The measure d vo lt age will be displayed. For DC
measur em en t, the polarity of the red lead wil l be
indica te d.

4.10.5 P re ss “FUNC” to switch between DC and AC
voltag e.

66 66

17 1 8

4.11 Resistance

Resist an ce r anges: 660.0、6.600k、66.00k、66 0. 0k、

6.600M、6 60 .0 0M.
To measure r es is tance:

4.11.1 Move rotary sw it ch t o the position.

4.11.2 Connect the re d te st l ead to the Ω jack and the
black le ad t o th e COM jack.

4.11.3 Connect lead s to c ir cuit under test.

4.11.4 The measured resistanc e wi ll b e displayed.

4.12 Contin uity

While in r es is tance mode, press “FUNC” to swi tc h to
contin ui ty m ode.

4.12.1 C on ne ct the red test lead to the Ω jack and th e
black le ad t o th e COM jack

4.12.2 .C on nect leads to circuit under tes t.

4.12.3 .I f th e measured resistance is less t ha n 50 Ω, the
meter’s buzzer will sound.

4.13 Diode Test

While in c on ti nuity mode, press “FUNC” to swi tc h to
diode mo de .

4.13.1 C on ne ct the red test lead to the V jack and th e
black le ad t o th e COM jack.

4.13.2 .C on nect leads across the diode und er t es t.

4.13.3 .T he d isplay shows the approx. forw ar d vo ltage
drop.

Ω

4.14 Capaci tance

4.15 Freque ncy and Duty Cycle

Freque nc y ra nges: 60Hz, 600Hz, 6kHz, 60kH z, 6 00 kHz,
6MHz, 60 MH z.
Measur in g Fr equency:

4.15.1 M ov e th e rotary switch to the Hz% positi on .

4.15.2 C on ne ct the red test lead to the Hz% jack an d th e
black le ad t o th e COM jack.

4.15.3 C on ne ct the leads across the circuit u nd er t est.

4.15.4 The measure d fr eq uency will be displayed.

4.15.5 P re ss “ FUNC” to switch to duty cycle.

4.15.6 R ep ea t steps 2-4 to measure duty cycle .

4.16 DC/AC Cu rrent

Curren t ra ng es: 660A, 6600A, 66.00mA, 660 .0 mA ,

10.000 A.

4.16.1 Tu rn o ff power t o th e ci rcuit and discharge all
capaci to rs f ully.

4.16.2 M ov e th e rotary switch to the appropri at e cu rrent
positi on ( µA , mA, or A)

4.16.3 C on ne ct the black test lead to the COM jac k. If t he
curren t to b e me asured is less than 600mA,
connec t th e re d test lead to the µAmA jack.If the
curren t to b e me asured is between 600mA and
10A, con ne ct t he red test lead to the 10A jack.

Capaci ta nce ranges: 6.6nF、66.00nF、660.0 nF、

6.600F、6 6. 00 F、66.0F、6.600mF and 66mF.
Measur in g ca pacitance:

4.14.1 M ov e th e rotary switch to the position .

4.14.2 C on ne ct the red test lead to the jack and th e
black le ad t o th e COM jack.

4.14.3 C on ne ct the leads across the capacit or f or
measur em en t

4.14.4 The measure d ca pa citance will be displayed

19 2 0

4.16.4 C on ne ct the leads in series to the circu it u nd er
test (brea k ci rcuit and connect red lead to the
relati ve ly h igher voltage side and black le ad t o
relati ve ly l ower voltage side).

4.16.5 Tu rn p ow er back on to circuit and the measu re d
curren t wi ll b e displayed. If the display sho ws
“OL”, it mea ns t he current exceeds the selected
range; m ov e th e rotary switch to the next highest
range.

5. Maintenance

5.1 Replaci ng the Battery

Remove t es t le ads from any circuit before ope ni ng

batter y co ve r to avoid electric shock injur y.

Warning

5.1.1 “ ”

Note:

If the symbol app ea rs, it indicated the battery

needs to b e re pl aced.

5.1.2 Lo os en t he screw and remove battery cov er.

5.1.3 Re pl ac e the used battery with a new one.

5.1.4 Re pl ac e the battery cover and tighten s cr ew.

Pay atte nt io n to the polarity of the battery to a vo id
damage t o th e me ter.

5.2 Replace P robe

If leads n ee d to b e replaces, they must be replaced
with one s th at a re of the same electrical
specif ic at ions.: 1000V, 10A

Warning

If insul at io n on leads is damaged, replace te st l ea ds.

NCV

25

00-05-0000

6. Accessories

Test leads

Manual

Batter y

9V 6F22

CD ROM dis c

1PC

1PC

1PC

1PC

1PC

USB inte rf ac e cable

USB inte rf ac e

5)

4)

3)

2)

1)