How does a multimeter reduce measurement errors? Choosing the appropriate range is very important
When measuring with a multimeter, whether measuring voltage or current, you must consider how to reduce the measurement error. In addition to mastering some measurement procedures, choosing an appropriate range is also a measure to reduce errors.
How to reduce measurement errors with multimeters
1. Before measurement, place the multimeter horizontally and perform mechanical zero adjustment.
2. When reading, keep your eyes vertical to the pointer;
When observing data, when the reflection of the pointer shadow cannot be seen on the mirror, it indicates that the line of sight is correct, and the data obtained at this time is the most accurate; if the reflection of the pointer shadow can be seen on the mirror, it indicates that the line of sight is skewed and should be corrected. Correction, otherwise errors will occur.
3. When measuring resistance, zero adjustment must be performed every time you change gears. If it cannot reach zero, replace the battery with a new one;
4. When measuring resistance or high voltage, do not hold the metal part of the test lead with your hands to avoid shunting of human body resistance, increasing measurement error or causing electric shock;
5. When measuring the resistance in the RC circuit, cut off the power supply in the circuit, discharge the electricity stored in the capacitor, and then measure again.
6. Choose the appropriate measuring range
For the selection of measuring range, when the amount of electricity being measured is unknown, set the measuring range to the highest gear to prevent damage to the meter due to excessive electricity being measured.
If the starting angle of the hands is too small, gradually lower the gear so that the hands point to the right of the entire dial.
For example, when measuring a DC voltage of 20V, if the measuring range is set to the 25V range (MF30 type), the meter needle will indicate at the right position (that is, more than 2/3 of the entire dial); if the 100v range is used, the meter needle will indicate the left position. (That is, 1/5 of the entire dial). At this time, the 100V gear has a larger error than the 25v gear.
