MM-960 - Multimeter Ferm - Free user manual and instructions

Product Type	Digital Multimeter
Model	MM-960
Brand	Ferm
Display	3 1/2 digit LCD, max readout 1999
Operating Temperature	0 to 40°C, relative humidity <75%
Storage Temperature	-10 to +50°C
Power Supply	9V battery (type 6LR62, MN 1604 or similar)
Battery Low Indication	Yes, symbol on display
Max DC Voltage	1000V
Max AC Voltage	700V RMS
Max DC Current	20A (15 seconds max)
Max AC Current	20A (15 seconds max)
Resistance Range	Up to 20MΩ
Diode Test	Yes, test current 1mA, reverse voltage 2.8V
Continuity Test	Yes, built-in buzzer sounds below 30Ω
hFE Measurement	Yes, with socket for NPN/PNP transistors
Input Impedance (DC/AC V)	10MΩ
Fuse Protection	0.2A/250V fuse (for mA/A range); 20A range unfused
Guarantee	24 months from purchase date
Maintenance	Keep clean and dry; do not use solvents
Accessories	Test leads, 9V battery, manual

Frequently Asked Questions - MM-960 Ferm

How do I measure DC voltage with the MM-960?

Connect the black test lead to the COM terminal and the red lead to the V/Ω terminal. Set the range switch to the desired V= position (start at highest range if unknown). Touch the probes to the circuit or source. Read the value on the display. The polarity is indicated; if red is negative, a minus sign appears.

What does a display showing only '1' mean?

A display showing only '1' indicates an overload or out-of-range condition. This means the measured value exceeds the selected range. Switch to a higher range. If it persists, the signal may be too high for the meter.

How do I replace the battery?

Turn the function switch to OFF and remove the test leads. Loosen the screws on the back cover and remove it. Replace the 9V battery with a new one (type 6LR62, MN 1604 or similar). Reattach the cover and tighten screws.

How do I replace the fuse?

Set the switch to OFF and remove test leads. Open the back cover. Locate the blown fuse (0.2A/250V) and replace it with an identical one. Close the cover. The 20A range is unfused; do not exceed 20A for more than 15 seconds.

What is the maximum voltage the MM-960 can measure?

The maximum input voltage is 1000V DC or 700V AC RMS. Higher voltages cannot be measured and may damage the meter or cause injury.

How do I perform a continuity test?

Connect the black lead to COM and red to V/Ω. Set the function switch to the continuity position (often marked with a diode or sound symbol). Touch the probes to the circuit. The buzzer sounds if the resistance is less than 30Ω, indicating a closed circuit.

How do I test a diode?

Connect the black lead to COM and red to V/Ω. Set the switch to the diode test position. Touch the probes to the diode: red to anode, black to cathode. The display shows the forward voltage drop (around 0.5-0.8V for silicon). Reverse connection shows '1' (open).

How do I measure hFE of a transistor?

Set the range switch to hFE. Insert the transistor into the correct socket (NPN or PNP) matching the emitter, base, and collector pins. The display shows the approximate DC gain (hFE) at a base current of 10μA and Vce 2.8V.

Why is accuracy different on different ranges?

Accuracy is specified as a percentage of reading plus a number of digits. For example, DC voltage on 200mV range: ±0.5% of reading ±1 digit. Higher ranges may have lower accuracy (e.g., ±0.8% ±2 digits). Always check the manual for the specific range.

How should I store the multimeter when not in use?

Turn the function switch to OFF to save battery. Remove the test leads. Store in a dry, clean place away from high humidity, high temperatures, and strong magnetic fields. Remove the battery if storing for an extended period to prevent leakage.

USER MANUAL MM-960 Ferm

Digital multimeter displaying 000Ω, connected to a coiled probe (no visible text or symbols on the device body)

Ferm MM-960

Digital Multimeter

• 3 1/2 Digit Liquid Crystal Display (max. readout: 1999):
• Operation temperature: 0 .... 40(C (rel. humidity <75%);
- Storing temperature: -10 ... +50(C;
• Power supply: 9V battery (type 6LR62, MN 1604 or similar);
• "Battery LOW" indication: "It:
- Calibration: Accuracy will be guaranteed for a period of 1 year, at 23(C + / - 5^ and a relative humidity of < 75% ;
- Electronic ON/OFF switch.

READ THIS USER'S MANUAL CAREFULLY!

2. USAGE

Your multimeter can be used to perform measurements of direct voltage (VDC), direct current (ADC), alternating voltage (VAC), alternating current (AAC) resistance ( , Ohm) and diodes-, continuity test and hFE-transistor measurement.

3. KNOW YOUR PRODUCT

Read this user's manual carefully and pay attention to the safety rules in particular, before you put your multimeter into use. Maintain your multimeter according to the instructions, to keep it in good shape. Do not use your multimeter, until you really understand the operation procedures. Keep this manual in a safe place, together with the other documentation of your device.

4. GENERAL SAFETY RULES

Your device has been developed with the greatest care for safety. Any modification or extension of the design can undo the safety. The guarantee can also be cancelled for that reason.

Keep your working area neat and tidy:

- An untidy working environment can cause acci-

dents.

- Provide sufficient lighting in your working environment

Be aware of the impact of your working area Never use your multimeter in a moist or wet area. Never leave it in the rain.

Keep children away

Never let other persons use your multimeter. Keep them out of the working area.

Store your tools in a safe place

Keep your multimeter in a dry place, if you do not use it.

Never overload your multimeter

You will work better and safer within the indicated power range. The guarantee will not cover damage due to overload.

Never use the measuring cord in the wrong way. Never carry your device, holding it with the measuring cord. Do not pull the cord to remove the plug from your multimeter. Always pull the plug itself.

Maintain your multimeter carefully

Keep your multimeter clean, for better and safer performances. Keep it dry and far from oil and grease.

Remove the measuring plug from your multi-meter

If you do not use your multimeter.

Check your tools for damage

- Try the safety facilities or damaged parts carefully on their excellent and purposive performance, every time before you use your device.

- Check if all conditions have been met, which may influence the performance of your device.

5. SPECIAL SAFETY RULES

I. WARNING! Measuring high voltages or currents can endanger your life. Never touch the bare parts of the measuring cords, when you measure voltages higher than 40 Volt or currents over 20 mA.
2. Your multimeter is a measuring instrument. Never hit or drop it.
3. Turn the switch to the OFF-position to save the battery, when you do not use your multimeter.
4. Keep your device far from high humidity or high temperatures.
5. Keep your multimeter far from strong magnetic fields.
6. Remove the battery to prevent leakage, when you intend to put your multimeter out of use for a long time.
7. Remove the cords immediately, when you smell

Fig.1

stinking insulation.

1. Use your multimeter, only if it is closed.

6. GUARANTEE CONDITIONS

1. Ferm has thoroughly proved this product and vouches for the good quality of manufacturing and material. Ferm grants a 24 MONTHS guarantee, from the date of purchase, covering every material and production fault, that might occur. Any other kind of claim on compensation, direct or indirect, to persons and/or materials, will be rejected.

2. First, consult your Ferm dealer. Usually, your dealer will be able to eliminate the problem or the failure.

3. The term of guarantee cannot be extended, by repairing or replacing parts within the guarantee period.

4. Normal wearing will not be covered by the guarantee; e.g. switches are not covered and also damage due to out-of-range measurements.

5. YOUR RIGHT ON GUARANTEE WILL ONLY BE VALID IF:

- a proof of the date of purchase can be shown, in the form of a purchase receipt;

- the associated guarantee certificate has been signed and filled in completely;

- neither third parties have carried out any repair or modification on the device, nor any non-original part has been assembled;

- the device has been treated, according to the operation instructions;

- there are no circumstances beyond our control. 6. The guarantee conditions will apply in conjunction with the terms of delivery and deliveries of sol

1. The transport costs of the device to be repaired will come to the account of the buyer. Badly wrapped articles will be rejected.

2. The guarantee certificate is enclosed in the back of this manual.

7. ENVIRONMENTAL PROTECTION

Regaining of resources is better than wasting them! Your device must be delivered in a solid wrapping, to avoid damage due to transport. This wrapping has been made of recyclable material, such as paper, cardboard and wood. We recommend to recycle the wrapping as much as possible.

Your multimeter contains a battery. Never waste this battery when it got empty, but hand it in as "Small Chemical Waste".

For replacement of the battery, refer to chapter 13 "Replacing the battery".

8. FERM AFTER-SALES SERVICE

Keep the original wrapping. Using this original wrapping will minimize the probability of transport damage, if your device still has to be transported. In case of a guarantee claim, your device must be presented in the strongest possible wrapping, preferably the original one. Each Ferm product has been proved with utmost accuracy, before leaving the factory. Consult your Ferm dealer, if your device still gets out of order.

9. BEFORE USING YOUR DEVICE

1. Set the turning knob to the highest range, if you do not know the voltage and/or current to be measured. Adjust the turning knob one measuring-range lower and so on, if the accuracy is not enough.

2. Set the turning knob to OFF, if you do not use your device.

3. The difference between the measurement of voltage and current is based on the circuit of your multimeter: Parallel for voltage and in series for current measurements. In the latter case, a conductor will have to be interrupted.

4. Never connect a source or charge to your multi-meter, with the FUNCTION-switch in Ω or → position.

5. Never connect a voltage over 1000 VDC or 700 VAC rms to your multimeter.

10. OPERATION

(SEE FIG. 1)

A. LCD display. Large 3 1/2 digit display, with a readout upto 1999. Indications for decimal point, polarity, overload and empty battery.

B. On/Off switch.

C. Range switch. Rotary switch to set the range.

D. hFE transistor measurement

E. 20A. Positive connector for measuring currents above 200 mA and upto 20A.

F. mA. Positive connector for the measurement of currents upto 200 mA.

G. COM. Negative connector

H. V/Ω. Positive connector for voltage and resistance measurements.

11. MEASURING

II.1 Measuring direct voltage (VDC)

1. Connect the BLACK cord to the "COM"-connector and the RED cord to the "V/Ω"-connector.

2. Set the FUNCTION-switch to the desired "V" = position and put the cords over the respective source or charge. Mind the correct polarity (red is +, black is -), otherwise the display will show a minus-sign before the value.

3. Readout the value in Volt.

RANGE ACCURACY RESOLUT.
200mV	± 0,5% of rdg ± 1 digit	100sV
2V		1mV
20V		10mV
200V		100mV
1000V	± 0,8% of rdg ± 2 digit	1V

Input resistance is 10 MSΩ

Overload security: DC or AC peak value is 1000V.(except the 200mV range which has a max. value of 250V rms)

NB:

I. In case you do not know the voltage range, set the FUNCTION-switch to the highest range and turn it down gradually, if necessary.

1. Set the FUNCTION-switch to a higher range, when only the figure "1" is displayed. In this case, the value is out of range.

2. The maximal input voltage is 1000 V. Higher voltages cannot be measured.

3. Take the utmost care, when measuring high voltages.

11.2 Measuring alternating voltage (VAC)

1. Put the BLACK cord to the "COM"-connector and the RED one to the "V/Ω"-connector.

2. Adjust the FUNCTION-knob to the desired "V\~" position and connect the cords to the source or charge to be measured. The polarity of the measuring pins is insignificant.

3. Readout the value in Volt.

RANGE ACCURACY RESOLUT.
200mV	= 1,2% of rdg ± 3 digits	100 _1 V
2V	= 0,8% of rdg ± 3 digits	1mV
20V		10mV
200V		100mV
700V IV ≤	1,2% of rdg ± 3 digits

Input resistance: 10 MS2

Frequency range for 700V range: 40 ... 200 Hz; for 200V or below: 40...400Hz. Overload security: AC 700 rms or DC 1000V peak.(Continuous on all ranges, except for 200 mV range with 250V rms). Indication: Average value (rms of sine shape)

NB:

1. In case the voltage range is unknown, set the FUNCTION-switch to the highest range and turn it down gradually, if necessary.

2. Set the FUNCTION-switch to a higher range,

when only the figure "I" is shown on the display. In this case, the value is out of range.

1. The maximum input range amounts 700 V. Higher voltages cannot be measured.
2. Take the utmost care, when measuring high voltages.

11.3 Measuring direct current (ADC)

I. Connect the BLACK cord to the "COM"-connector. Connect the RED cord to the "mA" connector, for measuring up to 2A. Connect the RED cord to the "20A max" point, for measuring within a higher current range, up to 20A.
2. Set the FUNCTION-switch to the desired "A" = position and connect the cords in series to the respective charge. Mind the correct polarity (red is + and black is -), otherwise the display will add a minussign to the value. The polarity of the RED cord will be shown, simultaneously with the value of the current.
3. Readout the value in (milli) Ampere.

RANGE ACCURACY RESOLUT.
200	± 0,8% of rdg = 3 digit	0,1Ω
2k	± 0,8% of rdg = 1 digit	1Ω
20k		10Ω
200k		100Ω
2M		1kΩ
	± 1% of rdg = 2 digit/20M	0kΩ

Overload protection: 2A/250V fuse, 20A range is not fused.
Max. input current: 20A, 15 seconds.
Max. voltage drop: 200 mV.

NB:

1. In case you do not know the current range, set the FUNCTION-switch to the highest range and lower it gradually, if necessary.
2. Set the FUNCTION-switch to a higher range, when only the figure "I" is displayed. In this case, the value is out of range.
3. The 20A range is not protected with a fuse. Never measure for more than 15 seconds.

11.4 Measuring alternating current (AAC)

I. Put the BLACK cord to the "COM"-connector and the RED cord to the "mA" connector, for measuring up to 2A. Connect the RED cord to the "A" print for measuring high current power up to 20A.
2. Set the FUNCTION-switch to the desired "A-" position and connect the cords in series to the respective source or charge. Mind the right polarity (red is + and black is -), otherwise the display will add a minus-sign to the value. The polarity of the RED cord will be shown, simultaneously with the value of the current.
2. Set the FUNCTION-switch to the desired "A-" position and connect the cords in series to the respective source or charge. Mind the right polarity (red is + and black is -), otherwise the display will add a minus-sign to the value. The polarity of the RED cord will be shown, simultaneously with the value of the current.

1. Readout the value in (milli) Ampere.

RANGE ACCURACY RESOLUT.
200μA	+1,6% of rdg ± 3 digits	0,1μA
2mA	+1,2% of rdg ± 3 digits	1μA
20mA		10μA
200mA	±2% of rdg ± 3 digits	100μA
2A		1mA
	+3% of rdg ± 7 digits70A

Overload protection: 2A/250V fuse, 20A range is not fused.

Frequency range: 40...400 Hz

Max. input current: 20A, 15 seconds

Max. voltage drop; 200 m

Indication: Average value (rms of sine shape).

NB:

1. In case you do not know the current range, set the FUNCTION-switch to the highest range and turn it down gradually, if necessary.

2. Set the FUNCTION-switch to a higher range, when only the figure "I" is displayed. In this case, the value is out of range.

3. The 20A range is not protected with a fuse. Never measure for more than 15 seconds.

11.5 Measuring resistance (Ω OHM)

1. Put the BLACK cord on the "COM" connector and the RED one on "V/Ω". (NB. The polarity of the red cord is "+"

2. Set the FUNCTION knob to the desired "Ω"-range.

3. Connect the measuring pins to the respective component. Take care that the component is not connected to other components and do not touch the points of the measuring pins, in order to prevent inaccuracy of the resistance value.

4. Readout the value in Ω (Ohm)

RANGE ACCURACY RESOLUT.
200	± 0,8% of rdg ≤slant 3 dig?	0,1Ω
2k	± 0,8% of rdg ≥slant 1 dig?	1Ω
20k		10Ω
200k		100Ω
2M		1kΩ
	± 1% of rdg ≥slant 2 dig?20M	10kΩ

Overload security: 250 YDC or AC. If less than 1.5 seconds.

Voltage open circuit: below 700 mV

1. Current from the internal battery will be used, for

the measurement of resistance's. The electricity consumption will vary with the range you have set.

NB:

1. "I" will be shown on the display, in case the measured resistance value exceeds the maximum value of the selected range. Select a higher range. It can take a few seconds for the meter to stabilize with a resistance of about 1 MΩ or higher. This is normal when measuring high resistance's.

2. If the input is not connected, e.g. for an interrupted circuit, the figure "I" will be shown on the display, to indicate that the value is out of range.

3. In case the respective resistance is connected to a circuit: Switch off the voltage and take care that every condensator has been fully discharged, before starting the measurement.

11.6 Measuring diodes

Connect the BLACK cord to the "COM"-connector and the RED one to the "V/Ω"-connector. (NB. The polarity of the red cord is "+"

1. Set the FUNCTION-switch to the range and connect the measuring pins to the respective diode. When measuring, the polarity of the measuring pins will determine whether the diodes or transistors are measured in the forward or reverse direction. The test current in forward direction will be 1 mA, the test voltage in reverse direction will be 2.8 V. Overload protection: 250 VDC or AC (less than 15 seconds). The value on the display will be the voltage over the diode in forward direction.
2. "I" will be shown on the display, when the measuring cords are not or wrongly (= in reverse direction) connected to the diode.

11.7 Continuity test

1. Put the BLACK cord to the "COM"-connector and the RED one to the "V/Ω" (NB. The polarity of the red cord is "+"

2. Set the FUNCTION-switch to the -rank and connect the measuring pins to the respective circuit.

3. In case the resistance is less than 30 , the buzzer will sound.

4. Open circuit voltage: 2.8 V, overload protection: 250 VDC or AC (less than 15 seconds)

11.8 hFE transistor measurement

1. Set the switch in the "hFE" position
2. Determine the type of the transistor (NPN or PNP) and connect the emitter-, base- and collector cords to the correct opening in the panel on the front.
3. The display will show the approximate hFE-value, at a base current of 10 μA, Vce 2.8 V.

12. MAINTENANCE

NOTE: Always remove the battery from your multi-

meter, when maintaining and cleaning. Never use water or any other kind of fluid to clean your device.

Keep the measuring cords of your multimeter clean. Some cleansing agents or solvents (petrol, thinner) can affect or solve the plastic parts. These products contain benzene, trichloroethylene, chloride, ammonia and so on.

13. TROUBLE

In case your multimeter does not function as it should, the following could be the cause:

Your multimeter does not show anything on the display

The battery is empty.

- Replace the battery

You have measured a current or voltage, which turned out to be too high, and your multimeter got damaged in spite of the protections.

- Hand your multimeter to the Ferm dealer, for repair.

Your multimeter does not indicate any value

The fuse is blown.

- Replace the fuse.

One or both measuring cords got damaged.

- Replace the cords.

You have measured a current or voltage, which turned out to be too high, and your multimeter got damaged in spite of the protections.

- H and your multimeter to your Ferm dealer, for repair.

REPLACING THE FUSE

I. Turn the switch to the OFF-position.

1. First, remove the back of your multimeter, by loosening the screws.

NOTE: Switch off your multimeter and remove the measuring cords, before opening the cover of your multimeter.

1. The blown fuse should be removed and replaced with a fuse of the same amperage and speed (0.2A/250V)

REPLACING THE BATTERY

I. The display will indicate a battery sign, when the battery is almost empty.

1. Put the turning knob to the OFF-position.

2. First, remove the back of your multimeter, by loosening the screws.

NOTE: Switch off your multimeter and remove the measuring cords, before opening the cover of your multimeter.

1. Now, replace the 9V battery with a new one.

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I. TECHNISCHE DATEN

REPLACEMENT DU FUSIBLE

6. CONDITIONS DE GARANTIE