Content

• To step
• Part 1 of 3: Reading the scale
• Part 2 of 3: Reading an analog multimeter
• Part 3 of 3: Troubleshooting
• Tips
• Warnings

The indications on a multimeter can look like a secret language to the layman and even people with experience in the field of electronics can use some help from time to time with an unfamiliar multimeter with deviating abbreviations. Fortunately, it does not take much time to translate the settings and understand how to read the scale, so that you can continue with your work.

To step

Part 1 of 3: Reading the scale

1. Test AC or DC voltage. Generally gives V. the voltage, a wavy line indicates alternating current (as you find in home electrical installations) and a straight or dotted line indicates direct current (like that in a battery). The line can be placed next to or above the letter.
   • The setting for testing voltage in an AC circuit is usually marked as V ~, ACV or VAC.
   • To test the voltage of a DC circuit, set the multimeter to V–, V ---, DCV or VDC.
2. Set the multimeter to measure current. Since current is measured in amperes, it is abbreviated to a. Now choose direct current or alternating current, whatever the circuit you are going to test is made for. Analog multimeters usually do not have the ability to test the current.
   • A ~, ACA and AAC are intended for alternating current.
   • A-, A---, DCA and ADC are intended for direct current.
3. Find the settings for the resistance. This is indicated by the Greek letter omega: Ω. This is the symbol for ohms, the unit of resistance. On older multimeters this is also indicated with R. for resistance.
4. Use DC + and DC-. If your multimeter has this setting, keep it set to DC + while testing a DC circuit. If you are not getting a reading and you suspect that you have attached the positive and negative measuring needles to the wrong ends, switch to DC- to correct it without having to adjust the wires.
5. Understand the other symbols. If you are unsure why there are different voltage, current, or resistance settings, read the troubleshooting section for more information on measuring ranges. In addition to these default settings, most multimeters have a number of additional settings. If more than one of these markers is next to the same setting, it may be that both are being measured at the same time, or you will need to consult the manual.
   • ))) and similar parentheses indicate the "continuity test". With this setting, the multimeter will beep when the two measuring needles are electrically connected.
   • A straight arrow with a cross through it marks the "diode test" for testing if one-way circuits are connected.
   • Hz stands for Hertz, the unit for measuring the frequency of AC circuits.
   • It –|(– symbolizes capacity.
6. Read the designation for the inputs. Most multimeters have 3 ports or inputs. Sometimes the gates are indicated with symbols similar to those described above. If these symbols are not clear to you, consult the following guide:
   • The plug of the black measuring needle always goes into the port with the label COM, which stands for common (also called earth). The other end of the black measuring needle cord is connected to the negative terminal.
   • When you measure the voltage or resistance, the plug of the red measuring needle goes into the port with the indication for the smallest current (often this is mA for milliamps).
   • When you measure the current, the red needle plug goes into the port labeled to withstand the amount of current expected. Usually this port for low-voltage circuits has a fuse with a load capacity of up to 200mA, while the gate for circuits through which a stronger current flows can be loaded up to 10A.

Part 2 of 3: Reading an analog multimeter

1. Find the correct scale on the analog multimeter. Analog multimeters have a needle that moves behind a glass plate to indicate the result. Usually there are 3 arcs behind the needle. These are the different scales, each of which has a different purpose:
   • The Ω scale is for measuring resistance. This is usually the largest bowl and is at the top. In contrast to the other scales, the 0 (zero) value is on the far right instead of on the left.
   • The "DC" scale is for reading the DC voltage.
   • The "AC" scale is for reading the AC voltage.
   • The "dB" scale is the least used option. See the end of this section for a brief explanation.
2. Read the voltage based on the selected range. Look closely at the voltage scale, either DC or AC. There should be several rows of numbers below the scale. See which range you have selected on the dial (for example 10 V) and find the corresponding label next to one of the rows. This is the row for which you should read the result.
3. Guess the value between the numbers. The voltage scale of an analog multimeter works in the same way as a ruler. The resistance scale, however, is logarithmic, meaning that the same distance on the scale is a different change in value depending on where you are on the scale. The lines between two numbers still indicate equal parts. For example, if there are three lines between "50" and 70, "they represent 55, 60 and 65, even though the distances between the lines are of unequal size.
4. Multiply the resistance reading on an analog multimeter. Look at the range setting of the multimeter. This will give you a value to be able to multiply the reading you read. For example, if the multimeter is set to R x 100 and the needle points to 50 ohms, the actual resistance across the circuit is 100 x 50 = 5000.
5. Find out more about the dB scale. The "dB" (decibel) scale, often the lowest and smallest of an analog multimeter, requires some extra training to use. It is a logarithmic scale that measures the voltage ratio (also called gain or loss). The standard dBv scale in the USA defines 0dbv as 0.775 volts, measured over 600 ohms resistance, but there are other scales as well, such as dBu, dBm and even dBV (with a capital V).

Part 3 of 3: Troubleshooting

1. Set the range. Unless you have a multimeter that sets the range automatically, each of the standard modes (voltage, resistance, and current) has several settings to choose from. This is the range you will have to set before attaching the probes to the circuit. Start with your best guess of the value just above the nearest result. For example, if you expect to measure 12 volts, set the meter to 25V, not at 10V, assuming these are the two closest options.
   • If you have no idea what current to expect, set it to the highest value first to avoid damaging the multimeter.
   • Other modes are less likely to damage the multimeter, but assume the lowest resistor setting and default to 10V.
2. Adjust the "out of range" value. On a digital multimeter, "OL," "OVER," or "overload" means you should choose a higher range, while a result very close to zero means you should choose a lower range for greater accuracy. On an analog multimeter, a pointer that stays still means that you have to choose a lower range. A pointer that moves past the maximum means that you will have to choose a higher range.
3. Remove the current from the circuit before measuring resistance. Turn off the power switch or remove the battery from the circuit to get an accurate measurement of resistance. The multimeter uses its own current to measure resistance, and if there is already current on the circuit, it will affect the result.
4. Measure the current in series. To measure the current you will have to make a circuit with the multimeter "in series" with the other components. For example, disconnect a live wire from a contact of a battery. Attach one gauge to the wire and one to the battery to close the circuit.
5. Measure the voltage in parallel. Voltage is the change in electrical energy in part of a circuit. The circuit should be closed and there should be a current on it. The multimeter should now place both measuring needles at different points in the circuit, "parallel" to the circuit.
6. Calibrate the ohm scale on an analog multimeter. Analog multimeters have an extra knob which is used to adjust the resistance scale and is usually indicated with an Ω. Before you measure the resistance in a circuit, hold the two measuring needles together. Turn the knob until the ohm scale reads zero to calibrate and then do the actual test.

Tips

• If there is a mirror behind the needle of your analog multimeter, turn the multimeter to the left or right so that the needle thinks up its own reflection and you can read more accurately.
• If you do not understand the values ​​as indicated on a digital multimeter, consult the manual. By default, a numeric value will be indicated, but there may also be a setting for displaying bar graphs or other ways of displaying information.
• If the needle of an analog multimeter is below zero, even in the lowest range, the "+" and "-" connectors are likely to be backwards. Swap the connectors and measure again.
• The initial reading will fluctuate when you measure the AC voltage, but this will eventually stabilize in an accurate reading.

Warnings

• Failure to select a range higher than the expected output from the circuit or battery could result in damage to your multimeter. Analog multimeters are often much more vulnerable than digital multimeters, while digital multimeters with automatic range selection are the sturdiest of all.