V A INSTRUMENT MS8221 Pocket Size Digital Multimeter User Manual

: June 4, 2024
: V A INSTRUMENT

Table of Contents

V A INSTRUMENT MS8221 Pocket Size Digital Multimeter
SAFETY INFORMATION

V A INSTRUMENT MS8221 Pocket Size Digital Multimeter

SAFETY INFORMATION

WARNING
To ensure safe operation, and in order to exploit to the full the functionality of the meter, please follow the directions in this section carefully.
This multimeter has been designed according to IEC61010 concerning electronic measuring instruments with an overvoltage category CAT III 600V and pollution 2. Follow all safety and operating instructions to 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.

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 been damaged in transit.
When poor conditions under harsh preservation or shipping conditions are caused, inspect and confirm this meter without delay.
Test leads must be in good condition. Before using verify that the insulation on test leads is not damaged and/or the leads wire is not exposed.
Full compliance with safety standards can be guaranteed only if used with test leads supplied. If necessary, they must be replaced with the same model or the same electric ratings.

DURING USE

Before using, you must select the right input jack, function, and range.
Never exceed the protection limit values indicated in specifications for each range of measurement.
When the 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 600V 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 leads from the circuit under test.
Never perform resistance, temperature, diode and continuity measurements on live circuits.
Never use the meter under the condition of the explosive air, steam or dirt.
If any faults or abnormalities are observed, the meter can not be used any more and it has to be checked out.
Never use the meter unless the rear case is in place and fastened fully.
Please do not store or use meter in areas exposed to direct sunlight, high temperature, humidity or condensation.

SYMBOL

Caution: refer to the instruction manual. Incorrect use may result in damage to the device or its components.
Earth:
**This instrument has double insulation.
Fuse:** F 250mA/600V 10A/600V

MAINTENANCE

Please do not attempt to adjust or repair the meter by removing the rear case while the voltage is being applied. A technician who fully understands the 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 an electricity attack, when the meter displays , you must change the battery.
For continued protection against fire, replace the fuse only with the specified voltage and current ratings: F 250mA/600V (quick acting),10A/600V (quick acting).
Do not use abrasives or so5lvents on the meter, use a damp cloth and mild detergent only.
Always set the power switch to the OFF position when the meter is not in use.
If the meter is to be stored for a long period of time, the batteries should be removed to prevent damage to the unit.

DESCRIPTION

This meter is a portable professional measuring instrument with a handsome LCD that easily reads.
The 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 home applications.
This meter is with the function of data hold.

NAME OF COMPONENTS

LCD display
Hold key
Rotary switch
Terminals

SPECIFICATIONS

GENERAL SPECIFICATIONS

Environment conditions: 600V CAT.III
Pollution degree: 2. Altitude < 2000 m.
Operating temperature: 0~40OC (32℉ to 104℉), (<80% RH, non-condensing)
Storage temperature: 10~50 OC(14℉ to 122℉), (<70% RH, battery removed)
Temperature Coefficient: 0.1×(specified accuracy) / OC (<18 OC or >28 OC)
MAX. The voltage between terminals and earth ground: 600V AC RMS or 600V DC
Fuse Protection: mA: F 250mA/600V ∅6.3×32,
10A: 10A/600V ∅6.3×32
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: 9V
Battery type: 6F22 9V
Dimensions: 158(L)×74(W)×40(H) mm.
Weight: 220g. Approx. (battery included).

Measurement specifications
Accuracy: ±(% of reading + number of digits) at 18°C to 28°C (64°F to 82°F) with relative humidity to 80%. (Accuracy is specified for a period of one year after calibration)

DC VOLTAGE

Range	Resolution	Accuracy
A/B/D model	C model
0.2V	0.1mV	±0.5%±2
2V	1mV	****

±0.5%±3

| ±0.5%±3
20V| 0.01V| ±0.8%±3
200V| 0.1V
600V| 1V| ±0.8%±2| ±0.8%±5

Input impedance: A/B/D
model: 10MΩ
C model: 1MΩ
Max. input voltage: 200mV range: 250VDC or AC RMS
2V – 600V ranges: 600VDC or 600V RMS

AC VOLTAGE

Range	Resolution	Accuracy
A/B/D model	C model
2V	1mV	****

±0.8%±4

| –
20V| 10mV| –
200V| 0.01V| ±1.2%±5
600V| 1V| ±1.2%±3

Input impedance: A/B/D
model: 10MΩ
C model: 1MΩ
Max. input voltage: 200mV
range: 250VDC or AC RMS
2V -600V ranges: 600VDC or 600V RMS
Frequency range: A/B/D
model: 40Hz-1000Hz
C model: 40Hz-400Hz
Response: Average, calibrated in terms of the sine wave.

DC CURRENT

Range	Resolution	Accuracy
A/B model	D model	C model
200uA	0.1uA	±0.8%±2
2mA	1 uA	±0.8%±2

±1.5%±2

20mA| 10 uA
200mA| 100uA| ±1.2%±2
10A| 10mA| ±2.0%±5| ±3.0%±2

Overload protection: F250mA/600V 10A/600V.
Max. Input Current: mA
Jack: 200mA, 10A
Jack: 10A

AC Current (A/B/D model)

Range	Resolution	Accuracy
2mA	1mA	±1.2%±3
20mA	10mA
200mA	0.1mA	±2.0%±3
10A	10mA	±3.0%±7

Overload protection: F250mA/600V 10A/600V.
Max. input current: mA: 200mA dc or 200mA ac RMS
10A: 10A 15 sec. Max
Frequency Range: 40Hz-1kHz
Indication: Average (RMS of sine wave)

Resistance

Range	Resolution	Accuracy
A/B/D model	C model
200Ω	0.1Ω	±0.8%±3
2KΩ	1Ω	****

±0.8%±2

| ****

±1.0%±2

20KΩ| 10Ω
200KΩ| 100Ω
2MΩ| 1kΩ
20MΩ| 10kΩ| ±1.0%±2| –

Overload protection: 250V DC or 250V AC rms.

Diode test
Display: read the approximate forward voltage of the diode
Forward DC Current: approx. 1mA
Reversed DC Voltage: approx. 2.8V
Overload protection: 250V DC or 250V AC RMS
Audible continuity test
The 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

Audible continuity test (Only B model)

Range	Description	Test Condition

CFE

| The display read approx. HFE value (0-1000) of the transistor under test (all types).| Base Current approx. 10μA, Vce approx. 2.8V.

Temperature (Only C model)

Range	Resolution	Accuracy
-20℃ to 0℃	****

1℃

| ±5.0%±4
0℃ to 400℃| ±1.0%±3
400℃ to 1000℃| ±2.0%±3

Overload Protection: 250V DC or RMS AC

Battery Test (Only D model)

Range	Accuracy	Discharge current
1.5V	±0.8%±2	100mA
9V	6mA

Overload protection: 1.5V: F250mA/600V fuse
9V: 250Vdc or 250Vac RMS

OPERATING INSTRUCTION

Voltage measurement

Set the rotary switch to the desired Vor V~ range.
Connect the black and red test leads to the COM and V terminals respectively.
Connect the test leads to the circuit being measured
Read the displayed value. The polarity of the red test lead connection will be indicated when making a DCV measurement.
When only 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 voltage measurement that might exceeds 600Vdc or 600Vac rms. Do not apply more than 600Vdc or 600Vac rms between the common terminal and the earth ground.

Current measurement

Set the rotary switch to the desired Aor A~ range.
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.
Connect test leads in series with the load in which the current is to be measured.
Read the displayed value. The polarity of the red test lead connection will be indicated when making a DCA measurement.
When only figure “1” is displayed, it indicates an overrange situation and the higher range has to be selected.
The c model doesn’t have an 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 an overrange situation and the higher range has to be selected.
When the value scale to be measured is unknown beforehand, set the range selector at the highest position.
means the socket of INPUT maximum current is 200mA, over current will destroy the fuse. 10A’s maximum current is 10A, load 15sec each 10min.

Resistance measurement

Connect the black test lead to the COM jack and the red test lead to the Ω jack.
Set the transform switch at the Ω range position.
Connect test leads across the resistance under measurement.
You can get reading from LCD.

To avoid electrical shock and/or damage to the instrument, disconnect the circuit power and discharge all high-voltage capacitors before measuring resistance.

NOTE:

For measuring resistance above 1MΩ, the meter may take a few seconds to stabilize the 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 over-range indication “1” will be displayed.

Diode test

Set the rotary switch to range.
Connect the black and red test leads to the COM and Ω terminals respectively.
Connect the red test lead to the anode, and the black test lead to the cathode of the diode under testing.
The meter will show the approx. the forward voltage of the diode. If the lead connection is reversed, only figure “1” is displayed.
To avoid electrical shock and/or damage to the instrument, disconnect the circuit power and discharge all high-voltage capacitors before testing diodes.

Continuity test

Set the rotary switch to range.
Connect the black and red test leads to the COM and Ω terminals respectively.
Connecting the test leads to the resistance in the circuit being measured.
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.

Temperature measurement (Only C model)

Set the transform switch at the TEMP range position.
The LCD display will show the current environment temperature.
When measuring the temperature with a thermocouple, a ‘K’ type probe for this meter can be used. Insert the black plug into the COM jack and the red one into the TEMP jack, and touch the end of the temperature sensor to the area or surface of the object for measurement.
You can get reading from LCD.

Battery test (only D model)

Set the rotary switch to desired BATT. range.
Connect the black and red test leads to the COM and VΩ terminals respectively.
Connect the test leads across the battery terminals under measurement.
Read LCD display and determine if the battery is OK.

Transistor measurement (only B model)
To avoid electrical shock and/or damage to the instrument, before attempting to insert transistors for testing, always be sure that test leads have been disconnected from any measurement circuits

Set the rotary switch to hFE range, plug the transistor adpertor.
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.

MAINTENANCE

General Maintenance

Periodically wipe the case with a damp cloth and mild detergent. Do not use abrasives or solvents.
Dirt or moisture in the terminals can affect readings.
To clean the terminals:
Turn the meter off and remove all test leads.
Shake out any dirt that may be in the terminals.
Soak a new swab with a cleaning and oiling agent (such as WD-40).
Work the swab around in each terminal. The oiling agent 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

Fuse replacement

To replace the Meter’s fuse (see the Figure):
Set the rotary switch to the OFF range.
Disconnect test leads from any input terminals.
Use a screwdriver to unscrew the 5 screws secured on the back casing.
Separate the back casing from the top casing.
Replace the fuse only with specified ratings: F 250mA/600V F 10A/600V
Replace the back casing and secure it with the 5 screws.
Before replacing the fuse, disconnect test leads from any circuit under test.
To prevent damage or injury, replace the fuse only with specified ratings.

Battery replacement

To replace the battery (see the Figure):
When the battery voltage drop below the proper operating range the symbol will appear on the LCD display and the battery needs to be replaced.
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 9V batteries (6F22).
Reinstall the battery cover and secure it with 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 terminals.

ACCESSORIES

Test Leads: one set
Battery: 9V, 6F22: three pieces
Instruction Manual in English: one piece
Thermocouple (K type) (Only C model): one piece

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.