Mastech MS8268 Скачать руководство пользователя страница 13

Note:

Note:

Note:

Note:

Reading is possible at input voltages above 3V rms, but the

accuracy is not guaranteed.

In noisy environment, it is preferable to use shield cable for

measuring small signal.

B)

B)

B)

B) To

To

To

To measure

measure

measure

measure frequency

frequency

frequency

frequency by

by

by

by AC

AC

AC

AC Voltag

Voltag

Voltag

Voltage

e

e

e (or

(or

(or

(or AC

AC

AC

AC Current)

Current)

Current)

Current)

range

range

range

range

Set the rotary switch to the desired range (AC Voltage or

AC Current).

Connect the black and red test leads to the

COM

COM

COM

COM

and

V

V

V

V

(or

mA

mA

mA

mA

) terminals respectively.

Connect the meter to the signal source; then press Hz/%

key.

For 5V logic signals (TTL), use the 4Vdc range. For 12V

switching signals in automobiles, use the 40Vdc range.

Read the frequency of the AC signal on the display.

To make a duty cycle measurement, press the

Hz

Hz

Hz

Hz %

%

%

%

key again.

Read the percent of duty cycle on the display.

Note:

Note:

Note:

Note:

If the reading is 0.000Hz or is unstable, the input signal may

be below or near the trigger level.

These problems can frequently be fixed by selecting a lower

range, which increases the sensitivity of the meter. In the

DCV function, the lower ranges also have lower trigger

levels.

If a reading seems to be a multiple of what you expect, the

input signal may be distorted.

21

Distortion can cause multiple triggering of the frequency

counter. Selecting a higher voltage range might solve this

problem by decreasing the sensitivity of the meter. Also, try

selecting a dc range, which raises the trigger level. In

general, the lowest frequency displayed is the correct one.

3.2.

3.2.

3.2.

3.2.8

8

8

8 Current

Current

Current

Current measurement

measurement

measurement

measurement

To

To

To

To avoid

avoid

avoid

avoid damage

damage

damage

damage to

to

to

to the

the

the

the Meter

Meter

Meter

Meter or

or

or

or injury

injury

injury

injury if

if

if

if the

the

the

the fuse

fuse

fuse

fuse

blows,

blows,

blows,

blows,

never

never

never

never

attempt

attempt

attempt

attempt

an

an

an

an

in-circuit

in-circuit

in-circuit

in-circuit

current

current

current

current

measurement

measurement

measurement

measurement where

where

where

where the

the

the

the open-circuit

open-circuit

open-circuit

open-circuit potential

potential

potential

potential to

to

to

to

earth

earth

earth

earth is

is

is

is greater

greater

greater

greater than

than

than

than 250V.

250V.

250V.

250V.

To

To

To

To avoid

avoid

avoid

avoid damage

damage

damage

damage to

to

to

to the

the

the

the meter,

meter,

meter,

meter, check

check

check

check the

the

the

the meter's

meter's

meter's

meter's

fuse

fuse

fuse

fuse before

before

before

before proceeding.

proceeding.

proceeding.

proceeding. Use

Use

Use

Use the

the

the

the proper

proper

proper

proper terminals,

terminals,

terminals,

terminals,

function,

function,

function,

function, and

and

and

and range

range

range

range for

for

for

for your

your

your

your measurement.

measurement.

measurement.

measurement. Never

Never

Never

Never

place

place

place

place the

the

the

the probes

probes

probes

probes in

in

in

in parallel

parallel

parallel

parallel with

with

with

with a

a

a

a circuit

circuit

circuit

circuit or

or

or

or

component

component

component

component when

when

when

when the

the

the

the leads

leads

leads

leads are

are

are

are plugged

plugged

plugged

plugged into

into

into

into the

the

the

the

current

current

current

current terminals.

terminals.

terminals.

terminals.

The Meter's current ranges are 400.0

µ

A, 4000

µ

A, 40.00mA,

400.0mA, and 10.00A.

To measure current:

1. Turn off power to the circuit. Discharge all high voltage

capacitors.

2. Set the rotary switch to the

µ

A, mA or A range.

3. Press the

SELECT

SELECT

SELECT

SELECT

key to select DCA or ACA measuring

mode.

4. Connect the black test lead to the

COM

COM

COM

COM

terminal and the

red test leads to the mA terminal for a maximum of

400mA. For a maximum of 10A, move the red test lead

to the

10

10

10

10A

A

A

A

terminal.

22

Содержание MS8268

Страница 1: ...Mastech MS8268 HANDHELD DIGITAL MULTIMETER OPERATOR S INSTRUCTION MANUAL http www HisTest com ...

Страница 2: ...aver 14 3 1 5 Relative measurement mode 14 3 2 Measurement Functions 15 3 2 1 AC and DC Voltage measurement 15 Ⅰ Table Table Table Table of of of of Contents Contents Contents Contents TITLE TITLE TITLE TITLE PAGE PAGE PAGE PAGE 3 2 2 Resistance measurement 16 3 2 3 Diode Test 17 3 2 4 Continuity Check 18 3 2 5 Transistor measurement 18 3 2 6 Capacitance measurement 19 3 2 7 Frequency and Duty Cyc...

Страница 3: ...otected internal MAINS derived circuits In the latter case transient stresses are variable for that reason requires that the transient withstand capability of the equipment is made known to the user 1 When using this Multimeter the user must observe all normal safety rules concerning Protection against the dangers of electric current Protection of the Multimeter against misuse For your own safety ...

Страница 4: ...ents on power switching circuits remember that high amplitude voltage pulses at the test points can damage the multimeter Use of a TV filter will attenuate any such pulses Use three 1 5V AAA batteries properly installed in the Meter s battery case to power the Meter 3 Replace the batteries as soon as the battery indicator appears With a low battery the Meter might produce false readings that can l...

Страница 5: ...switched off If any faults or abnormalities are observed take the instrument out of service and ensure that it cannot be used until it has been checked out If the meter is not going to be used for a long time take out the battery and do not store the meter in high temperature or high humidity environment 1 2 1 2 1 2 1 2 Safety Safety Safety Safety mechanisms mechanisms mechanisms mechanisms Miscon...

Страница 6: ...lay Display Symbols Symbols Symbols Symbols continued continued continued continued Symbol Symbol Symbol Symbol Meaning Meaning Meaning Meaning REL REL REL REL Indicator for the Relative measurement Indicator for the Diode Test mode hFE hFE hFE hFE Indicator for the transistor test mode Indicator for the Continuity Check mode Indicator for the Data Hold mode V V V V mV mV mV mV V mV Volts The unit...

Страница 7: ...counter mode 9 Table Table Table Table 2 2 2 2 Keypad Keypad Keypad Keypad continued continued continued continued Key Key Key Key Function Function Function Function Operation Operation Operation Operation performed performed performed performed HOLD HOLD HOLD HOLD Any Any Any Any switch switch switch switch position position position position Press HOLD HOLD HOLD HOLD to enter and exit the Data ...

Страница 8: ... and and and ranges ranges ranges ranges 1 The red lights at the V and COM terminals will be off after the test leads are plugged in 2 The buzzer will sound upon misconnection of the test leads in the mA or 10A terminals to warn the user At the same time the lights at the V and COM terminals will flash to remind the user to plug in the test leads there At At At At μ μ μ μA A A A mA mA mA mA and an...

Страница 9: ...ging mode AUTO AUTO AUTO AUTO turns off Each presses of RANGE RANGE RANGE RANGE key increments the range When the highest range is reached the Meter wraps to the lowest range 13 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 ret...

Страница 10: ...d value The polarity of red test lead connection will be indicated when making a DCV measurement NOTE NOTE NOTE NOTE ℕ 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 15 ℕ For better accuracy when measuring the dc...

Страница 11: ... a forward bias reading of 0 5V to 0 8V however the reverse bias reading can vary depending on the resistance of other pathways between the probe tips 3 2 4 3 2 4 3 2 4 3 2 4 Continuity Continuity Continuity Continuity Check Check Check Check To To To To avoid avoid avoid avoid electrical electrical electrical electrical shock shock shock shock and or and or and or and or damage damage damage dama...

Страница 12: ...pacitance The measurement takes about 1 second per range The Meter s capacitance ranges are 4 000nF 40 00nF 400 0nF 4 000µF 40 00µF and 200 0µF 19 To measure capacitance 1 Set the rotary switch to range 2 Connect the black and red test leads to the COM COM COM COM and terminals respectively or you can measure the capacitance by using the special Multi Function Socket 3 Connect the test leads to th...

Страница 13: ...or injury injury injury injury if if if if the the the the fuse fuse fuse fuse blows blows blows blows never never never never attempt attempt attempt attempt an an an an in circuit in circuit in circuit in circuit current current current current measurement measurement measurement measurement where where where where the the the the open circuit open circuit open circuit open circuit potential pot...

Страница 14: ...re Coefficient 0 1 specified accuracy 18 or 28 ℕ MAX Voltage between terminals and earth ground 750V AC rms or 1000V DC ℕ Fuse Protection µA and mA Resettable fuse 400mA 250V 23 10A F 10A 250V 6 3 32 mm ℕ Sample Rate 3 times sec for digital data ℕ Display 3 3 4 digits LCD display Automatic indication of functions and symbols ℕ Range selection automatic and manual ℕ Over Range indication LCD will d...

Страница 15: ...x 0 5V Overload protection 250Vdc or 250Vac rms 25 4 2 4 2 4 2 4 2 5 5 5 5 Diode Diode Diode Diode Range Resolution Function 1mV Display read approx forward voltage of diode Forward DC Current approx 1mA Reversed DC Voltage approx 1 5V Overload protection 250Vdc or 150Vac rms 4 4 4 4 2 2 2 2 6 6 6 6 Transistor Transistor Transistor Transistor Range Description Test Condition hFE Display read appro...

Страница 16: ... current 400mA dc or 400mA ac rms for µA and mA ranges 27 4 2 4 2 4 2 4 2 9 9 9 9 DC DC DC DC CURRENT CURRENT CURRENT CURRENT Range Resolution Accuracy 400µA 0 1µA 1 2 of rdg 3 digits 4000µA 1µA 40mA 0 01mA 400mA 0 1mA 10A 10mA 2 0 of rdg 5 digits Overload protection F 10A 250V fuse for 10A range Resettable fuse F400mA 250V for µA and mA ranges Maximum input current 400mA dc or 400mA ac rms for µA...

Страница 17: ... only with with with with specified specified specified specified ratings ratings ratings ratings To replace the Meter s fuse see Figure 2 1 Set rotary switch to the OFF position 29 2 Disconnect test leads and or any connectors from the terminals 3 Use a screwdriver to unscrew the two screws secured on the battery cover 4 Take out the battery cover from the meter 5 Remove the fuse by gently prying...

Страница 18: ...use Replacemen Replacemen Replacemen Replacement t t t CAUTION CAUTION CAUTION CAUTION Using this appliance in an environment with a strong radiated radio frequency electromagnetic field9approximately 3V m may influence its measuring accuracy The measuring result can be strongly deviating from the actual value 31 ...

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