To configure the electronic devices, and matching circuits must be aware of the resistance elements.
Sometimes it also becomes necessary to check the individual radio components (resistors, diodes, transformers of different function) resistance.
You will need
- - Ommetr-
- - Ampermetr-
- - Voltmetr-
- - Knowledge of Ohm's law.
The item or element in the investigated resistance, Disconnect the circuit. Start the measurement by turning instrument to measure the minimum resistance to the regime. If the readings are readable enough, you can step by step to move to higher value mode of resistance. Each meter has feelers, they are attached to the conclusions of the details. Before the measurements, it is necessary to read the instructions, especially what concerns the polarity. Polarity is important in measuring the resistance of semiconductor components.
The usual tester (avometrom) can be measuredresistance range from a few ohms to milliohms units. For higher resistances DC need additional power connection according to the instructions for the device. You can apply the calculation circuit resistance. For this item investigated include the circuit with a current source in series with an ammeter is included, and in parallel studied details - voltmeter. In this case resistance calculated by the formula: R = U / I, where R - voltage, U- resistanceAnd I - current in the circuit.
Some radioactive elements (e.g., semiconductors), have a different resistance for different directions of current. This should be considered when measuring by conducting reverse current measurement at lower values of the applied voltage. Otherwise researched item may be damaged.