Mastech ms8261 Operator'S Instruction Manual Download Page 9

Some tips for measuring capacitance:

( The meter may take a few seconds to stabilize reading. This is normal for high capacitance measuring.

( To improve the accuracy of measurements less than 20nF, subtract the residual capacitance of the

Meter and leads.

3.2.6 Transistor measurement

To avoid electrical shock and/or damage

to the instrument, do not apply more than

250Vdc or 250Vac rms between the hFE

terminal and the COM terminal.

1. Set the rotary switch to hFE range.

2. Connect the “com” plug and “+” plug of the special multi-function socket to the COM and hFE

terminals.

3. Determine whether the transistor to be tested is NPN or PNP type and locate the Emitter, Base and

Collector leads.

4. Insert leads of the transistor into proper holes of the special multi-function socket.

5. The meter will show the approx. hFE value at test condition of base current 10μA and Vce 2.8V.

3.2.7 Current measurement

To avoid damage to the Meter or injury if

the fuse blows, never attempt an in-circuit

current

measurement

where

the

open-circuit potential to earth is greater

than 250V.

To avoid damage to the meter, check the

meter's fuse before proceeding. Use the

proper terminals, function, and range for

your measurement. Never place the test

leads in parallel with a circuit or component

when the leads are plugged into the current

terminals.

Current is the flow of electrons through a conductor.

The Meter's DC current ranges are 2.000mA, 20.00mA, 200.0mA and 10.00A

AC current ranges are

2.000mA, 200.0mA and 10.00A.

To measure current:

1. Turn off the power of the measured circuit. Discharge all the high voltage capacitors.

2. Set the rotary switch to the proper range.

3. Connect the black test lead to the COM terminal and the red test leads to the mA terminal for a

maximum of 200mA. For a maximum of 10A, move the red test lead to the 10A terminal.

4. Break the circuit path to be tested.

Connect the black test lead to the more negative side of the break; connect the red test lead to the more

positive side of the break. (Reversing the leads will give a negative reading, but will not damage the

Meter.)

Summary of Contents for ms8261

Page 1: ... directly connected to the low voltage installation NOTE Examples are measurements on household appliances portable tools and similar equipment Measurement category I is for measurements performed on circuits not directly connected to MAINS NOTE Examples are measurements on circuits not derived from MAINS and specially protected internal MAINS derived circuits In the latter case transient stresses...

Page 2: ... avoid the risk of shock due to possible improper reading verify the presence of any ac voltages by first using the ac function Then select a dc voltage range equal to or greater than the ac range Disconnect circuits power and discharge all high voltage capacitors before testing resistance continuity diodes or capacitance Never perform resistance or continuity measurements on live circuits Before ...

Page 3: ...ergize and de energize circuits and equipment in accordance with established practices When the instrument is opened up remember that some internal capacitors can retain a dangerous potential even after the instrument is 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 goi...

Page 4: ...e absolute value of the input calibrated to indicate the equivalent rms value of a sine wave Indicator for dc voltage or current The Meter is in the Diode Test mode Table 1 Display Symbols continued The Meter is in the Continuity Check mode The Meter is in the Data Hold mode V mV V m V Volts The unit of voltage Millivolt 1x10 3 or 0 001 volts A mA A A m A A Amperes amps The unit of current Milliam...

Page 5: ...bout 5 seconds the backlight is auto off 2 4 Terminals See Table 4 indicated for information about the terminals Table 4 Terminals Termi nal Description COM Return terminal for all measurements Receiving the black test lead or the com plug of the special multi function socket V Input for voltage resistance diode and continuity measurements Receiving the red test lead mA hF E Input for capacitance ...

Page 6: ...c rms To avoid electrical shock and or damage to the instrument do not apply more than 1000Vdc or 750Vac rms between the common terminal and the earth ground Voltage is the difference in electrical potential between two points The polarity of ac alternating current voltage varies over time the polarity of dc direct current voltage is constant The Meter s DC voltage ranges are 200 0mV 2 000V 20 00V...

Page 7: ...tract for the resistance of the test leads The resistance function can produce enough voltage to forward bias silicon diode or transistor junctions causing them to conduct To avoid this do not use the 40M range for in circuit resistance measurements On 20M and 200M ranges the meter may take a few seconds to stabilize reading This is normal for high resistance measuring On 200M range the display is...

Page 8: ...llow key twice to activate Continuity Check 3 Connect the black and red test leads to the COM and terminals respectively 4 Connect the test leads to the resistance in the circuit being measured 5 When the test lead to the circuit is below approx 30 a continuous beeping will indicate it Note Continuity test is available to check open short of the circuit 3 2 5 Capacitance measurement To avoid elect...

Page 9: ...he fuse blows never attempt an in circuit current measurement where the open circuit potential to earth is greater than 250V To avoid damage to the meter check the meter s fuse before proceeding Use the proper terminals function and range for your measurement Never place the test leads in parallel with a circuit or component when the leads are plugged into the current terminals Current is the flow...

Page 10: ... MAX Voltage between terminals and earth ground 750V AC rms or 1000V DC Fuse Protection mA Resettable fuse F200mA 250V Sample Rate 3 times sec for digital data Display 3 1 2 digits LCD display Automatic indication of functions and symbols Over Range indication LCD will display 1 Low battery indication The is displayed when the battery is under the proper operation range Polarity indication display...

Page 11: ... Average calibrated in rms of sine wave 4 2 3 Resistance Rang e Resolut ion Accuracy 200 0 1 0 8 of rdg 3 digits 2k 1 0 8 of rdg 1 digit 20k 10 200k 100 2M 1k 20M 10k 1 0 of rdg 2 digits 200M 0 1M 5 0 of rdg 10digits 10 digits Overload protection 380V dc or 380Vac rms Open Circuit Voltage Less than 700mV 4 2 4 Diode Rang e Resoluti on Function 1mV Display read approx forward voltage of diode Forwa...

Page 12: ...tion Resettable fuse F200mA 250V 10A range unfused Max input current 200mA dc or 200mA ac rms for mA range 10A dc or 10A ac rms for 10A ranges For measurements 5A 4 minutes maximum ON to measure 10 minutes OFF Above 10A unspecified 4 2 9 AC Current Range Resolutio n Accuracy 2mA 1 A 1 0 of rdg 3 digits 200mA 0 1mA 1 8 of rdg 3 digits 10A 10mA 3 0 of rdg 7 digits Overload protection Resettable fuse...

Page 13: ...ing and oiling agent such as WD 40 Work the swab around in each terminal The oiling agent insulates the terminals from moisture related contamination 5 2 Battery replacement To avoid false readings which could lead to possible electric shock or personal injury replace the battery as soon as the battery indicator appears Before replacing the battery disconnect test leads and or any connectors from ...

Page 14: ...over Battery cover Figure 2 Battery and Fuse Replacement CAUTION Using this appliance in an environment with a strong radiated radio frequency electromagnetic field approx 3V m may influence its measuring accuracy The measuring result can be strongly deviating from the actual value ...

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