Mastech MS8221, User Manual

Page 1: ...ERATING INSTRUCTION 9 4 1 Voltage measurement 10 4 2 Current measurement 10 4 3 Resistance measurement 12 4 4 Diode test 12 4 5 Continuity test 13 4 6 Temperature measurement 13 4 7 Battery test 14 4 8 Transistor measurement 14 5 MAINTENANCE 15 User s Manual Mastech MS8221 ...

Page 2: ... ensure that the meter is used safely and is kept in good operating condition With proper use and care the digital meter will give you years of satisfactory service 1 1 PRELIMINARY When using the meter the user must observe all normal safety rules concerning Protection against the dangers of electrical current Protection of the meter against misuse When the meter is delivered check that it has not...

Page 3: ... value scale to be measured is unknown beforehand set the range selector at the highest position Do not measure voltage if the voltage on the terminals exceeds 1000V above earth ground Always be careful when working with voltages above 60V DC or 30V AC rms keep fingers behind the probe barriers while measuring Before rotating the transform switch to change functions and ranges disconnect test lead...

Page 4: ...y removing the rear case while voltage is being applied A technician who fully understands danger involved should only carry out such actions Before opening the battery cover or case of the meter always disconnect test leads from all tested circuits To avoid the wrong reading causing electricity attack when the meter displays you must change the Caution refer to the instruction manual Incorrect us...

Page 5: ... stored for a long period of time the batteries should be removed to prevent damage to the unit 2 DESCRIPTION This meter is a portable professional measuring instrument with handsome LCD easily reading Single operation of a transform switch makes measurement convenient Overload protection and low battery indication are provided this meter is ideal for use in the fields workshop school hobby and ho...

Page 6: ...4 hFE socket except MS8221D 5 Terminals 5 ...

Page 7: ...X Voltage between terminals and earth ground 750V AC rms or 1000V DC Fuse Protection mA F 200mA 250V 5 20 10A unfused Display LCD 1999counts updates 2 3 sec Over Range indication LCD will display 1 Low battery indication The is displayed on the LCD Polarity indication displayed automatically Power source 4 5V Battery type AAA 1 5V Dimensions 158 L 74 W 31 H mm Weight 220g Approx battery included 3...

Page 8: ...1MΩ Max input voltage 200mV range 250VDC or AC rms 2V 1000V ranges 1000VDC or 750V rms 3 2 2 AC VOLTAGE Accuracy Range Resolution MS8221A 8221D MS8221B 8230B 2V 1mV 20V 10mV 200V 0 01V 0 8 3 750V 1V 1 2 3 1 2 5 Input impedance MS8221A MS8221D 10MΩ MS8221B MS8230B 1MΩ Max input voltage 200mV range 250VDC or AC rms 2V 1000V ranges 1000VDC or 750V rms Frequency range MS8221A MS8221D 40Hz 1000Hz MS822...

Page 9: ... AC Current MS8221A MS8221D Range Resolution Accuracy 2mA 1µA 20mA 10µA 1 2 3 200mA 0 1mA 2 0 3 10A 10mA 3 0 7 Overload protection F250mA 250V fuse 10A range unfused Max input current mA 200mA dc or 200mA ac rms 10A 10A continuous 20A 15 sec Max Frequency Range 40Hz 1kHz Indication Average rms of sine wave 3 2 5 Transistor hFE Except MS8221D Display read approximate hFE value 0 1000 of transistor ...

Page 10: ...C rms 3 2 7 Diode test Display read approximate forward voltage of diode Forward DC Current approx 1mA Reversed DC Voltage approx 2 8V Overload protection 250V DC or 250V AC rms 3 2 8 Audible continuity test Built in buzzer sounds if resistance is less than approx 50Ω Open circuit voltage approx 2 8V Overload protection 250V DC or 250V AC rms 3 2 9 Temperature Only MS8221B Range Resolution Accurac...

Page 11: ... COM and V terminals respectively Connect the test leads to the circuit being measured Read the displayed value The polarity of red test lead connection will be indicated when making a DCV measurement When only the figure 1 is displayed it indicates overrange situation and the higher range has to be selected To avoid electrical shock and or damage to the instrument do not attempt to take any volta...

Page 12: ... indicated when making a DCA measurement When only the figure 1 displayed it indicates overrange situation and the higher range has to be selected MS8221B MS8230B don t have ACA measurement function To avoid damage to the meter use the proper terminals function and range for your measurement NOTE When only the figure OL is displayed it indicates overrange situation and the higher range has to be s...

Page 13: ...itors before measuring resistance NOTE For measuring resistance above 1MΩ the meter may take a few seconds to stabilize reading This is normal for high resistance measuring If the resistance being measured exceeds the maximum value of the range selected or the input is not connected an overrange indication 1 will be displayed 4 4 Diode test Set the rotary switch to range Connect the black and red ...

Page 14: ...easured When the test lead to the circuit is below 50Ω a continuous beeping will indicate it To avoid electrical shock and or damage to the instrument disconnect circuit power and discharge all high voltage capacitors before testing for Continuity 4 6 Temperature measurement Only MS8221B Set the transform switch at the TEMP range position The LCD display will show the current environment temperatu...

Page 15: ...urement Read LCD display and determine if the battery is OK 4 8 Transistor measurement Set the rotary switch to hFE range Determine whether the transistor to be tested is NPN or PNP type and locate the Emitter Base and Collector leads Insert leads of the transistor into proper holes of the hFE socket The meter will show the approx hFE value at test condition of base current 10μA and Vce 2 8V To av...

Page 16: ...gent insulates the terminals from moisture related contamination To avoid electrical shock or damage to the meter do not get water inside the case Remove the test leads and any input signals before opening the case 5 2 Fuse replacement To replace the Meter s fuse see the Figure Set the rotary switch to OFF range Disconnect test leads from any inputs terminals Use a screwdriver to unscrew the two s...

Page 17: ...placed Turn the meter off and remove all test leads Use a screwdriver to unscrew the two screws secured on the battery cover and remove the battery cover Replace the battery with three new 1 5V battery AAA Reinstall the battery cover and secure by the two screws Before replacing the battery disconnect test leads from any circuit under test turn the meter off and remove test leads from the input te...

Page 18: ... 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 17 ...