Precautions for measurement with an analog multimeter
A multimeter is a relatively precise instrument, and if used improperly, it can not only cause inaccurate measurements but also be easily damaged. However, as long as we master the usage and precautions of a multimeter, and approach it with caution, the multimeter can be durable and long-lasting. When using a multimeter, the following precautions should be taken:
(1) The measurement of current and voltage should not be rotated to the wrong gear. If the resistance or current mode is mistakenly used to measure voltage, it is easy to burn out the electricity meter. When the multimeter is not in use, turn the gear to the AC voltage gear to avoid damage due to improper use.
(2) When measuring DC voltage and DC current, pay attention to the "+" and "-" polarity and do not connect them incorrectly. If the pointer is found to be reversed, the meter rod should be replaced immediately to avoid damaging the pointer and the meter head.
(3) If the magnitude of the measured voltage or current is unknown, the gear should be used first, and then the appropriate gear should be selected for testing to avoid excessive deflection of the pointer and damage to the meter head. The closer the selected gear is to the measured value, the more accurate the measured value will be.
(4) When measuring resistance, do not touch the two ends of the component (or the metal parts of the two meter bars) with your hands to avoid parallel connection between human resistance and the measured resistance, which may result in inaccurate measurement results.
(5) When measuring resistance, if two meter bars are short circuited and the "zero ohm" knob is adjusted to, the pointer still cannot reach the 0 point. This phenomenon is usually caused by insufficient battery voltage inside the meter, and a new battery should be replaced to accurately measure.
(6) When the multimeter is not in use, do not turn it to the resistance mode, as there is a battery inside. If not careful, it can cause the two meter bars to collide and short circuit, which not only consumes the battery but can also damage the meter head in severe cases.
