For car enthusiasts, there are multi-purpose measuring devices that are designed specifically for measurements in a car. One such device can measure the crankshaft speed, the angle of the closed state of the breaker contacts, and, in addition, voltage up to 20 volts. The range of resistance measurements by such a device is usually limited to the kilo-ohm region, i.e. 1-1000 kOhm.
In addition, measuring instruments for testing electrical and electronic components are offered. They allow extensive measurements from small resistances in ohms (Ω) to very large resistances in megaohms (MOhm). Voltages (in volts) can be measured very accurately, which is especially required for electronic components.
When it is only necessary to check whether there is voltage in the circuit at all, a simple test lamp "A" can be used for this. First of all, it is only suitable for checking electrical circuits that do not have any electronic components. This is due to the fact that electronic components are extremely sensitive to high currents and under certain circumstances can fail even when the test lamp is connected.
Note: To check electronic components (transistors, diodes and control units) a voltage indicator with a high internal resistance "V" is required. It works as a test lamp, but does not cause damage to electronic components and is suitable for all testing work.