The structure of the multimeter and the meaning of each of the symbols and how to use them.
The multimeter consists of three main parts: the meter head, the measurement circuit and the changeover switch.
Meter head
It is a high sensitivity magnetoelectric DC ammeter, the main performance index of the multimeter basically depends on the performance of the head. The sensitivity of the head refers to the DC current value flowing through the head when the pointer of the head is deflected at full scale, the smaller this value is, the higher the sensitivity of the head is. The greater the internal resistance when measuring voltage, the better its performance. There are four scales on the head of the meter, their functions are as follows: the first one (from top to bottom) is marked with R or Ω, indicating the value of the resistance, the conversion switch is in the ohms, i.e., read this scale. The second marked with ∽ and VA, indicating the AC and DC voltage and DC current values, when the transfer switch in AC and DC voltage or DC current block, range in addition to AC 10V other than the other position, that is, read this scale. The third is labelled with 10V, indicating the AC voltage value of 10V. When the changeover switch is in the AC or DC voltage block and the range is at AC 10V, this scale is read. The fourth line is marked with dB, indicating the audio level.
Measurement line
Measurement line is used to convert a variety of measured to the appropriate meter to measure the tiny DC current circuit, which consists of resistors, semiconductor components and batteries
It can be a variety of different measurements (such as current, voltage, resistance, etc.), different ranges, after a series of processing (such as rectification, shunt, voltage, etc.) into a certain limit of the tiny DC current into the meter head for measurement.
Switch
Its role is to select a variety of different measurement lines to meet the requirements of different types and different ranges of measurement. Transfer switch generally have two, respectively marked with different gear and range.
