# How to Use a Universal Multimeter or Tester

#### How to Use a Universal Multimeter or Tester

Contents

Step 1: Measuring a voltage

Step 2: Measuring a current

Using a multimeter or a universal tester, you can measure several physical quantities:

• an AC or DC voltage expressed in volts (V);
• a resistance, expressed in ohms (Ω);
• a current, expressed in amperes (A).

Today, there are two types of universal testers: digital and analog. Some digital testers have the advantage of automatic gauge selection, making them much easier to use.

Always choose the highest rating of the quantity being measured if the rating selection is not automatic.

Reminder:

The ground wire is usually in the middle of the socket.

The letter N indicates the neutral (blue wire).

Caution: An electrical outlet can conduct electricity even if the appliance connected is not working. Use a voltmeter or a voltage tester to ensure that no current is flowing through the outlet.

# 1. Measuring a voltage

Measuring AC or DC voltage is done in the same way. It would help to connect the multimeter in parallel.

Example: for the mains, select 500 volts and AC.

Attention: on some devices, everything is grouped in a single zone marked V. In this case, select ~ (or AC) for alternating current and = (or DC) for direct current.

Select the highest rating corresponding to the voltage to be measured (10 volts, 20 volts, 500 volts, etc.).

Select the type of voltage to be measured: AC (symbol V~) or DC (symbol V=).

Set the center switch to the area marked VAC, ACV, or AC to measure AC voltage.

To measure a DC voltage, set the center selector to the area marked V, VDC, or DCV.

Measure the voltage with the red and black key tips.

If the voltage measured is DC, connect the multimeter’s minus (black) terminal to the minus of the installation.

Then connect the other terminal of the multimeter (red) to the point where you want to know the voltage: the measurement appears on your screen.

If you want a more precise measurement (as in the case of batteries), adjust the rating of your tester to approach the value indicated on the device.

Attention: the selected gauge must always be higher than the value of the voltage to be measured.

# 2. Measuring a current

To measure a current, you must connect the multimeter in series.

Caution: a current measurement is rarely carried out on the mains (danger of short circuit on the installation or electrocution), in which case a current clamp is used.

To take this measurement on a low voltage device (battery-powered):

Select the highest rating corresponding to the current to be measured (milliamperes, amperes, etc.).

Select the type of current to be measured: alternating (symbol A~) or direct (symbol A=).

Open the circuit at the location where you want to know the current.

Connect the two probe tips to the two break points in the circuit.