Ohmimittarit

Ohmimittarit, commonly known as ohmmeters, are electrical instruments used to measure electrical resistance. Resistance is the opposition to the flow of electric current in a circuit. Ohmmeters are essential tools for electricians, engineers, and hobbyists for diagnosing circuit problems, verifying component values, and ensuring proper circuit operation.

The basic principle behind an ohmmeter involves applying a known voltage to the component or circuit under test and measuring the resulting current. According to Ohm's law, voltage equals current multiplied by resistance (V=IR). By knowing the voltage and measuring the current, the resistance can be calculated. Modern ohmmeters often use an internal battery to provide the test voltage and a sensitive galvanometer or digital display to show the resistance reading, typically in ohms (Ω), kilohms (kΩ), or megohms (MΩ).

When using an ohmmeter, it is crucial that the circuit being tested is de-energized. Applying an ohmmeter to a live circuit can damage the instrument and provide inaccurate readings. Ohmmeters are available in various forms, including standalone analog and digital devices, as well as integrated functions within multimeters, which offer a wider range of measurement capabilities. Common applications include checking fuses, testing wires for continuity, identifying short circuits, and verifying the value of resistors.