How to measure power frequency with digital multimeter?
Some digital multimeters have a frequency test gear, directly dial the gear to the frequency Hz position, insert the red test lead into the V/Ω/Hz hole, and the black test lead into the com hole. On the socket, you can measure the power frequency.
How to measure power frequency with digital multimeter
The display structure of the measurement frequency in the above figure, the AC frequency of 50Hz, the actual measurement is 49.97, the result is more reliable, this is the operation method for measuring the low frequency frequency.
For the sake of safety, this method should not be used for the measurement frequency between the phase line and the phase line 380V to prevent damage to the input converter of the digital multimeter and personal safety.
If it is used to measure the detection frequency of induction cookers, you need to look at the frequency measurement range of the digital multimeter; the frequency measurement range of the cheap digital multimeter is narrow, the measurement accuracy is not high, and the error is relatively large, and it can only be used as a preliminary judgment for the presence or absence of frequency. .
For example, the Uteli UT61 digital multimeter, the price is about 430 yuan, the frequency measurement range is 10Hz~10MHz and 10Hz~220MHz, the measurement error is ±0.1%, and the frequency measured is relatively accurate.
It is simple to measure frequency with this digital multimeter. There is a common ground in the electronic circuit, commonly known as GND; connect the black test lead of the multimeter to GND, and the red test lead to the control pole (G) of the gate control tube (IGBT), and the oscillation frequency can be measured and displayed. ; Generally, the working frequency of the IGBT of the induction cooker is about 25~32KHz. It is strictly forbidden to connect the red test lead to the C pole of the IGBT. When the DC voltage is 300V, the digital multimeter will be damaged.
The gears of the slightly more expensive digital multimeters are all automatic shifting, which is very convenient to use. Do not use a multimeter to measure high frequency and high voltage beyond the frequency measurement range. First, the measurement results are generally poor, and second, it is easy to cause damage to the digital multimeter.
