Multimeter Procurement Tips and Operational Procedures
1. The display digits and accuracy of a multimeter
The display digit and accuracy are the most basic and important indicators of a multimeter. Generally speaking, the higher the number of digits displayed on a multimeter, the higher the accuracy, and vice versa.
2. Measurement method and AC frequency response of multimeter
The measurement method of a multimeter is mainly for measuring AC signals. With changes in the frequency of the AC signal, various frequency responses occur, which affect the measurement of the multimeter. There are generally two methods for measuring AC signals with a multimeter: average value and true effective value measurement.
3. Function and measurement range
Different manufacturers of multimeters will design different functional measurement ranges. Ordinary multimeters can test AC/DC voltage, current, resistance, on-off, etc., but some multimeters do not have a current function to reduce costs.
4. Measurement stability and protection
A good multimeter has good self-protection. For example, when some multimeters are plugged in the wrong probe wire, they will automatically sound a beep alarm... When choosing a multimeter, do not blindly pursue cheap prices, it should be practical and easy to use.
Instructions for using a multimeter
1. Before use, familiarize yourself with the various functions of the multimeter, and correctly select the gear, range, and probe socket according to the object being measured.
2. When the size of the measured data is unknown, the range switch should be set to the maximum value first, and then switched from the large range to the small range range, so that the instrument pointer indicates more than 1/2 of the full scale.
3. When measuring resistance, after selecting the appropriate magnification range, touch the two probes to make the pointer point to zero. If the pointer deviates from zero, adjust the "zero adjustment" knob to make the pointer return to zero to ensure accurate measurement results. If the zero cannot be adjusted or the digital display meter emits a low voltage alarm, it should be checked in a timely manner.
4. When measuring the resistance of a certain circuit, the power supply of the tested circuit must be cut off and live measurement is not allowed.
5. When using a multimeter for measurement, attention should be paid to personal and instrument safety. During testing, it is not allowed to touch the metal part of the probe with hands, and it is not allowed to switch the gear switch with electricity to ensure accurate measurement and avoid accidents such as electric shock and instrument burnout.
