Before using the multimeter, you should prepare for measurement
A multimeter is a portable instrument with multiple functions and ranges. A typical multimeter can measure DC current, DC voltage, AC voltage, and resistance. Some can also measure inductance and some parameters of semiconductors (such as β). Mastering the usage of a multimeter proficiently is a fundamental skill for electricians. So a multimeter is one of the essential instruments for electricians. Multimeters can be divided into pointer multimeters and digital multimeters.
Due to the variety of types of multimeters, it is necessary to prepare for measurement before use.
① Familiarize yourself with the functions of switches, knobs, sockets, etc., check the dial symbols, "" indicates horizontal placement, and "⊥" indicates vertical use.
② Understand the measured power corresponding to each scale line on the dial.
③ Check if the positions of the red and black probes are correct. Insert the red probe into the "+" socket and the black probe into the "-" socket. Some multimeters also have AC/DC 2500V high voltage measuring terminals. When measuring high voltage, the black probe does not move. Insert the red probe into the high voltage socket.
④ Mechanical zeroing. Rotate the mechanical zero adjustment screw on the multimeter panel to align the pointer with the "0" position on the left end of the dial.
Principle of measuring capacitance with a multimeter
Use a multimeter to measure the capacitance value based on the current variation over time during capacitor charging, and use a stopwatch to measure the time from the moment the capacitor is turned on to the selected end point to calculate the capacitance value. Firstly, set the multimeter to the resistance range and adjust the mechanical and zero settings. Then connect the capacitor and start timing until it reaches a point close to ∞, at which point the timing will end.
