How to use a Digital Multimeter effectively – Some Tips and …
Topics By Louis Spencer JR | November 20, 2018
A digital multimeter is the handiest tool for an electronics engineer, and to be successful in the industry, it is essential to be well versed in the functioning and usage of this tool. A digital multimeter is a lightweight, battery-operated device that can be used for measuring a variety of electrical values in a circuit, namely, voltage, current, and resistance. It also comes into use for testing diodes and measuring the continuity of a complex circuit, thereby making it an essential tool for the manufacturing, testing and repairing of electronic circuits.
This slide deck provides a comprehensive overview of the usage of a multimeter for its various purposes.
A) – Measuring Resistance
- Getting started – Before you start utilizing a multimeter for reading different values, you must connect the black probe to the common terminal (often marked as COM) and the red probe to the terminal for measuring Voltage and Resistance (often marked with a V, an Ohm symbol or a diode symbol).
- Select the parameter that you want to measure- In this case, you need to measure resistance, so turn the knob on the multimeter to point to the symbol for resistance (the Ohm symbol).
Now your multimeter is ready to measure the property of resistance.
- Turn off the power supply to the circuit – You should never remove a component from the circuit when the power supply is ON.
- Remove the resistor from the circuit carefully, without disturbing the rest of the circuit. It is important to take off the resistor from the circuit for an accurate measurement of resistance.
- Take the two probes and touch their tips to either end of the resistor and read the value being displayed by the multimeter. This reading provides you with the resistance of the component.
Tip – Always check what unit of resistance does the displayed value correspond to. The values may be in displayed in Ohms, Kilo Ohms, and Mega Ohms. For an accurate reading, select the appropriate range of resistance by turning the knob on the multimeter. e.g If you know that the resistance value falls in the range of 200-250 Ohms then point the knob to the 200 Ohm or 2 Kilo Ohms range.