Selection skills of multimeter sensitivity:
1) If the ranges selected by the two multimeters are the same but the voltage sensitivities are different, when they are used to measure the same high internal resistance power supply voltage, the measurement error of the meter with higher voltage sensitivity is smaller.
2) For the same multimeter, the higher the voltage range, the larger the internal resistance, and the smaller the measurement error caused.
In order to reduce the error of measuring the high internal resistance power supply voltage, sometimes it is better to choose a higher voltage range to increase the internal resistance of the multimeter. Of course, the range should not be too high, so as not to increase the reading error due to the too small deflection angle of the pointer when measuring low voltage. For power supply voltage with low internal resistance (for example, 220V AC power supply), a multimeter with lower voltage sensitivity can be used for measurement. In other words, high-sensitivity multimeters are suitable for electronic measurements, while low-sensitivity multimeters are suitable for electrical measurements.
3) When the internal resistance of the voltage block of the multimeter is more than 100 times larger than the internal resistance of the power supply under test, there is no need to consider the shunting effect of the multimeter on the power supply under test.
