MX-25304 - Multimeter Maxwell - Free user manual and instructions

Product Type	Digital Multimeter
Model	MX-25304
Display	4-digit LCD, max. 9999
Polarity	Automatic negative polarity indication
Overload Display	"OL"
Low Battery Indication	Battery symbol on screen
Measurement Method	A/D converter
Safety Standards	CE EMC/LVD, IEC1010, CAT II double insulation
Operating Environment	0-40 °C, <80% RH
Storage Environment	-20-60 °C, <80% RH
Power Supply	1 x 9V battery (IEC 6F22)
Dimensions	190 x 88.5 x 27.5 mm
Weight	422 g (with battery)
Accessories	Test leads (red/black), holster, K-type thermocouple probe, user manual
Measurement Functions	DC/AC voltage, DC/AC current, resistance, capacitance, frequency, inductance, temperature, diode test, continuity test, transistor hFE
DC Voltage Ranges	200 mV, 2 V, 20 V, 200 V, 1000 V
AC Voltage Ranges	200 mV, 2 V, 20 V, 200 V, 750 V
DC Current Ranges	2 mA, 20 mA, 200 mA, 20 A
AC Current Ranges	2 mA, 20 mA, 200 mA, 20 A
Capacitance Ranges	20 nF, 200 nF, 2 μF, 20 μF, 200 μF, 2000 μF
Resistance Ranges	200 Ω, 2 kΩ, 20 kΩ, 200 kΩ, 2 MΩ, 20 MΩ
Frequency Ranges	10 Hz, 100 Hz, 1 kHz, 10 kHz, 100 kHz, 1 MHz, 10 MHz
Inductance Ranges	2 mH, 20 mH, 200 mH, 2 H, 20 H
Temperature Range	-20 °C to 1000 °C (with K-type thermocouple)
Auto Power Off	After 15 minutes inactivity (can be disabled)
Fuse Protection	200 mA/250 V and 20 A/250 V ("F" marked)
Care and Maintenance	Wipe with damp cloth; replace battery and fuse as needed; store in cool, dry place

Frequently Asked Questions - MX-25304 Maxwell

How do I measure DC voltage with the MX-25304?

Set the range knob to the desired DCV range. Connect the black test lead to COM and the red test lead to V/Ω. Connect the probes in parallel to the circuit. Read the voltage on the LCD.

What does 'OL' on the display mean?

'OL' indicates overload, meaning the measured value exceeds the selected range. Select a higher range to get a reading.

How do I replace the battery?

Turn off the multimeter and disconnect test leads. Remove the battery cover on the back, slide out the old 9V battery, and insert a new one (IEC 6F22). Reattach the cover.

What is the maximum voltage I can measure?

For DC voltage, the maximum is 1000 V. For AC voltage, the maximum is 750 V. Exceeding these can damage the meter.

How do I test a diode?

Set the range knob to the diode/continuity position. Connect the black lead to COM and red to V/Ω. Touch the red probe to the anode and black to the cathode. The display shows the forward voltage drop (approx. 0.5-0.8 V for silicon diodes).

How do I measure resistance?

Set the range knob to the desired Ω range. Connect the black lead to COM and red to V/Ω. Ensure the circuit is de-energized and touch the probes to the resistor. Read the resistance value.

Can I measure current in the 20A range for a long time?

No, measuring current above 10 A in the 20A range should be limited to 15 seconds maximum to avoid overheating and fuse damage. The 20A range is not fuse-protected.

How do I use the Hold and Backlight function?

Press the Hold/Backlight key briefly to freeze the display (HOLD symbol appears). Press again to release. Long press the same key to toggle the backlight on/off.

How do I measure temperature?

Insert the K-type thermocouple plug into the COM (black) and V/Ω (red) jacks. Set the range knob to the temperature function. The display shows the temperature in °C (default). Press the Hold button to switch to °F.

How do I clean the multimeter?

Use a damp cloth to wipe the casing. Do not use chemicals, solvents, or abrasives. Ensure the meter is turned off and test leads are disconnected before cleaning.

USER MANUAL MX-25304 Maxwell

DIGITAL MULTIMETER DIGITÁLIS MULTIMÉTER MULTIMETRU DIGITAL DIGITÁLNY MULTIMETER

Product code / Termékkód / Cod produs / Kód produkta:

25304

GENERAL DESCRIPTION

Display	4 digit liquid crystal display max. value 9999
Polarity	Automatic negative polarity display
Nullification automatic
Measurement process	A/D converter
Overload display	only „OL” is displayed
Low battery power	The( [+] ) symbol appears on the screen
Safety prescriptions	CE EMC/LVD. Device complies to IEC1010 standard
Protection category	II, double insulation
Operating environment	temperature: 0...40 °C, relative humidity: < 80%
Storage environment	temperature: -20...60°C, relative humidity: < 80%
Battery 1 x 9V IEC 6F22 Battery
Dimensions	190 mm x 88,5 mm x 27,5 mm
Weight 422 g (with battery)
Accesories	Instructions, connection cable (red and black, 1 pair), hitting pocket protector, K-type thermometer probe

ELECTRICAL

CHARACTERISTICS

Accuracy +/- (% of displayed value + number of digits) at 23 +/-5 °C, < 75% relative humidity

DCV

Range Accuracy Resolution
200 mV	+/- (0,5% + 3)	0,1 mV
2 V 1 mV
20 V 10 mV
200 V 100 mV
1000 V +/- (0,8% + 10) 1 V

Input Impedance	10 MΩ
Overload protection (Range: 200 mV)	1000 VDC or AC peak value
	250 VDC or AC peak value

ACV

Range Accuracy Resolution
200 mV	+/- (0,8% + 5)	0,1 mV
2 V 1 mV
20 V 10 mV
200 V 100 mV
750 V +/- (1,2% + 10) 1 V

Input Impedance

10 MΩ

Frequency response	40 Hz - 1 KHz(sine wave and triangular wave)
	40 Hz - 200 Hz(other waves)

DCA

Range Accuracy Resolution
2 mA	+/- (0,8% +10)	1 μA
20 mA		10 μA
200 mA		100 μA
20 A +/- (2% + 5)		10 mA

Overload protection	20 A / 250 V fuse with "F" mark
	200 mA / 250 V fuse with "F" mark

ACA

Range Accuracy Resolution
2 mA		1 μA
20 mA 10 μA+/- (0,8% + 10)
200 mA 100 μA
20 A +/- (2% + 5) 10 mA

Overload protection	20 A / 250 V fuse with "F" mark
	200 mA / 250 V fuse with "F" mark

Frequency response	40 Hz - 1 KHz(sine wave and triangular wave)
	40 Hz - 200 Hz(other waves)

Capacitance

Range Accuracy Resolution
20 nF	+/-(3,5%+20)	10 pF
200 nF 100 pF
2 μF 1 nF
20 μF 10 nF
200 μF	+/-(5%+10)	100 nF
2000 μF 1 μF

Overload protection

DC 250V or AC peak value

Transistor hFE-Test

Function Description Test state
h_FE	The amplification factor of the transistor is measured (0-1000) (NPN or PNP)	Base current appr. 10 μA VCE appr. 3 V

Resistance

Range	Accuracy Resolution
200 Ω	+/- (0,8% + 5)	0,1 Ω
2 kΩ	+/- (0,8% + 3)	1 Ω
20 kΩ		10 Ω
200 kΩ		100 Ω
2 MΩ		1 kΩ
20 MΩ	+/- (1,0% + 25)	10 kΩ

Overload protection

250 V DC or AC peak value

The reading be displayed slowly when the measurement is more than 1 MΩ. Please wait it to be stable.

Temperature (with a K type temperature sensor)

Range Accuracy	Resolution
-20 °C - 1000 °C	+/- (1,5%+15)
0 °F - 1832 °F

Diode and Continuity Testing

Function	Reading Condition
	Forward voltage drop of diode	Forward DCA is approx. 1 mA, the backward voltage is approx. 3 V
	Buzzer makes a long sound while resistance is less than 70 Ω +/- 20 Ω	Opening voltage appr. 3 V

Overload protection

250 V DC or AC peak value

Frequency

Range Accuracy Resolution
10 Hz		0,01 Hz
100 Hz 0,1 Hz
1 kHz 1 Hz
10 kHz 10 Hz +/- (0,1%+3)
100 kHz 100 Hz
1 MHz/10 MHz 1 kHz/10 kHz

Overload protection

250 V DC or AC peak value (for maximum 10 seconds)

Input sensitivity 1 V RMS

Inductance

Range Accuracy Resolution
2 mH		1 μH
20 mH 10 μH
200 mH 100 μH/(2,5%+30)
2 H 1 mH
20 H 10 mH

Overload protection DC 36 V

Warning: Do not connect external voltage source to the connectors!

1. LCD: display the measuring value and unit
2. Function keys
   2-1. Power switch: turn on/off the power
   2-2. Hold and backlight key: short press to the measured value is held on LCD and "HOLD" symbol displays. Press it again "HOLD" symbol disappears and meter is exited the holding mode. Long press to turn on/off the backlight.
   2-3. Transistor test socket.
   2-4. Press "REL/MAX/MIN", then you can test the relative magnitude. If you hold the "REL/MAX/MIN" for more than 2s, you can test the Max and Min value.
3. Range knob: to select measuring function and range.
4. Voltage, resistance, frequency, capacitance, diode port - "V/Ω"
5. Common measuring port (COM)
6. Port for measuring current less than 200 mA and inductivity
7. Port for measuring current 20 A

Usage

button. If the battery is depleted, the battery symbol appears on the screen.

exceeding the inward voltage or current. This is to prevent damage to the inside circuits.

desired position.

result, set the switch to the highest possible range and go backwards until you reach the correct setting.

DC and AC voltage measuring

and the red one to the „V/Ω“ connector.

position and connect the wires to the voltage source paralelly.

Note:

to the highest possible range and go backwards until you reach the correct setting.

Switch to a higher range.

connectors. Results may be displayed at higher voltages also, but this may lead to damage to the inside circuits.

DC and AC current measuring

red one to the „mA“ connector (max. 200 mA) or the „20A“ connector for measuring 200 mA or 20 A.

A follow the instructions above, but connect the red wire to the „20A“ connector.

Note:

set the switch to the highest possible range and go backwards until you reach the correct setting.

overload. Switch to a higher range.

depending on the connector. (For maximum 15 seconds.) Too much currency overheats the fuse which needs to be replaced. The 20 A measuring range is not protected.

Resistance measuring

one to the „V / Ω“ connector.

range.

Warning: make sure that the measured circuit is not under power!

connector is 250 V RMS (for maximum 10 seconds).

Note:

threshold and the device signals overload („OL“), select a higher range. When measuring above 1 MW it may take a few seconds for the device to stabilize the displayed value. This is completely normal for such resistors.

a break) the display will show „OL“.

sure that the circuit is not under power and all capacitors are discharged.

damage to the inside circuits.

approximately 3 V.

Capacity measuring

Ω" and "COM" connector. Pay attention to the correct polarity.

Note:

selected range and the device signals overload („OL“). ^-3 μF or 1000 pF

Turn off the power and discharge the capacitors before measuring. Also discharge the electrolyte capacitors before measuring!

more times.

Diode and continuity test

„COM“, the red one to „V / Ω“ connector. (Note: the polarity of the red wire is: +)

•→+” position.

The screen shows the opening voltage of the diode.

the resistance is below 90 Ω the device beeps.

Note:

break) the display will show „OL”.

and overload if the diode is connected with the polarity reversed

Temperature measuring

measuring sensor to the „COM“ connector and the red one to the „V/Ω“ connector. Put the sensor to the place measured. The display shows the measured value in °C or °F (press "HOLD" button to select).

Note:

sensor.

displays the temperature of the environment.

device is in temperature measuring function.

Transistor hFE test

place it in the proper connector.

displayed on the screen.

Frequency measuring

cable to the „COM“ and „V / Ω“ connectors.

and touch the wires to the signal source. Note:

V(RMS).

measuring small values.

Inductance measuring

range.

and "COM" terminal. Remark:

at H range until overload signal turns off.

possible, do not connect such inductors to the connectors.

Auto Power Off

will be into sleep mode. Press "POWER" key can back to work.

with the "POWER" key the "APO" symbol will disappear, now you already closed the function of auto power off.

WARNING

wires are not connected to a current measuring connector and that the function switch is not in resistance or diode measuring measuring mode. Always check if you have connected the wires into the proper connectors.

especially with high voltage equipment.

connecting the multimeter to measure current and do not measure above 20 A.

sure the circuit is not under power.

appropriate for the measuring. If in doubt,

set the maximum measuring range and go backwards.

damaged.

all external power sources are turned off and that the multimeter is turned off as well.

CARE AND MAINTENANCE

Operation

immediately. The liquid corrodes the electric circuit.

only at normal temperature. High temperature can shorten the lifetime of electronic devices, damage to the batteries and distort, melt the plastic parts.

that can cause damage to the electric circuit and to the case which leads to the improper operation of the multimeter.

dirt which results in premature wear of the components.

cloth. Do not use chemicals, solvents or strong detergents for cleaning.

multimeter and pull out the test lead of the socket.

cover.

type of it.

Fuse replacement

OFF position and pull out the test lead of the socket.

cover.

valued (5x20 mm, 200 mA / 250 V „F“ signed.)

ÁLTALÁNOS LEÍRÁS