Digital Multimeter

User’s manual

Digital Multimeter- Definition

A multimeter is an electric measuring instrument to measure parameters such as, current, voltage, resistance, capacity, inductance, etc. Each instruments has a different range of measurements and is able to measure AC, DC or both depending of its specifications and functions. Some digital multimeters are capable of measuring other parameters, for example temperature

Magnitudes de medida y rangos The next table shows the most common parameters and magnitudes that a multimeter is able to

measure. However, it depends on the type of instrument and its specifications. There are several things than make a multimeter better than another, usually the wide of ranges and the accuracy in the measurements are a vital issue and they depends on how good the tool is; usually pre price is directly related; a better multimeter takes measurements more accurately or in a wide range, but this is not always true.

Parameters Common ranges of

measurement

AC Current Up to 10A or 20A

DC Current Up to 10A or 20A

AC Voltage Up to 750V

DC Voltage Up to 1000V

Inductance Up to 20H

Capacity Up to 9.999uF

Resistance Up to 50Mohm

Frequency Up to 10Mhz

Continuity Acoustic beep

Diodes Yes/ No

Temperature Up to 1000ºC (with probe)

Caution & Safety

Caution

Read the operation manual for operating the instrument safely and maintaining the instrument in a safe operating condition.

If the meter comes from a trusted supplier, the instruments has been tested, verified and the warranty will be included.

Safety

Multimeters fro professional use must meet some international safety standards which will determine the right use of the meter.

For example the digital multimeter Brymen BM 319 meets the standards CE/CAT. II for 1000V.

Warnings when measuring

with a multimeter Check the instrument protection against wrong uses.

Make sure the test leads are in good conditions.

Never overpass the limits specified for each type of measurement.

Do not touch the metallic part of the test leads during the measuring.

If doubt, better to star choosing the highest range for the parameter to measure.

Every time you want to change function, make sure the probes are not in contact with any type of current or voltage.

Pay special attention when measuring high voltage circuits.

Never measure resistance in active circuits.

These advises are general and they depend on the type of meter. These can be followed to operate multimeters such as the Brymen BM525

Maintenance of a digital

multimeter Change fuses when it is necessary.

If you think something is wrong with the meter, call the technical service.

Make sure the cover is close and screws are fasten.

Periodically wipe the case with a damp cloth and mild detergent; do not use abrasives or solvents.

If the meter is not to be used for several months, remove the batteries and store them separately.

Basic operations with a digital

multimeter I

This section includes the basic operations that a multimeter can make. Every instruments requires a different operation procedure, these are general procedures that work for some meters, for example the Brymen BM 525.

DC Voltage measurement

Chose de DC function en the slide-switch function-selector.

Plug the test leads, the black one goes in the COM jack and the red one in the V jack.

Resistance measurement

Chose de range of the function: ohms.

Plug the test leads, the black one goes in the COM jack and the red one in the OHM/V jack.

*Measuring voltage with this function may cause damage to the instrument.

Basic operations with a digital

multimeter II Continuity measurement

Choose the ohm function.

Press the select bottom until the continuity symbol shows up on the screen.

Plug the test leads, the black one goes in the COM jack and the red one in the OHM/V jack.

Take the test lead and make contact with the circuit.

Usually and acoustic sound will verify that there is continuity

Capacity measurement

Choose the continuity function.

Press the select bottom until the capacity symbol shows up on the display.

Place the test lead, the black one goes in the COM jack and the red one in the V jack.

Place the test lead on the circuit and watch the results on the display.

Basic operations with a digital

multimeter III

Diode test

Choose the diode test function.

Press the select bottom until the diode symbol shows up on the screen.

Place the test lead, the black one goes in the COM jack and the red one in the V jack.

Take the test lead and make contact with the circuit.

Do it again switching the test leads.

The display will show “OL” if the diode is good. Any other measurement will mean the diode is resistive or cut (faulty).

DC/AC measurement: uA, mA or Amps

Choose the A, mA or uA function.

Place the test lead, the black one goes in the COM jack and the red one in the mA, uA or A jack.

When the function is on, the instruments is set

to measure DC (by default). Press the select

bottom to change to AC measurements.

Basic operations with a digital

multimeter IV Protection system

Some digital multimeter have a protection function. A beep sound when the positions of the test leads is not according with the measurement function you have chosen.

Temperature measurements

Choose the temperature function.

Connect the temperature probe, the right jacks are COM (-) and TEMP(+).

If the meter is ready to measure the display will show the symbol: ºC.

HOLD function

Press the hold bottom to start this function, press again to exit. The reading will be frozen on the display when the function is on.

Basic operations with a digital

multimeter V HOLD MAX function

To start this mode press the button hold "HOLD" MAX during several seconds.

Auto Range or Manual function

Press the RANGE button to choose manual range. Press the button again to switch to Auto-range. When auto-rage is on the symbol: Auto will be on the display

Display with back light

Press the select button during several seconds to start the back light on the display. Do it again to turn it off.

Auto-power-off function

The meter turns off after X minutes of neither

switch nor button activity. Press any button and

the meter will turn back on.

Digital Multimeter: Front Panel Usually the front panel of a digital multimeter

consists of:

• A display that can be simple (image on the left)

or dual (image on the right)

• A switch to choose the

measuring parameter.

• Function buttons. For example, to turn the light on the display on.

• Jacks to plug the test leads and different types of probes.

Source – More info at:

Digital multimeters – Dagatron

Instruments

For more info about our digital

multimeters and other measuring

instruments send and email to

info@dagatron.es