How to measure the ground voltage of precision equipment with a multimeter
Precision equipment is to have absolutely good grounding, if not all kinds of power interference will affect the precision of precision equipment, the conventional method is to use megohmmeter shaking to the ground absolute resistance, but encountered precision equipment test electronic precision equipment that can not be used megohmmeter, because the megohmmeter generated by the high voltage will break through the components of precision electronic equipment, so also need to use the multimeter, the equipment is static when I use a multimeter on-site measurements are generally used to measure the resistance value between the equipment ground terminal and the standard ground. Pointer meter X1 gear to measure the equipment ground terminal and the standard ground between the resistance value, equipment dynamics directly with the multimeter DC voltage file to measure the equipment ground and the standard ground voltage, the general equipment to produce ground voltage when the voltage is not the standard DC voltage, it is recommended to use the pointer multimeter, the pointer multimeter can be a rough monitoring of the ground voltage condition of the equipment in different operating conditions, such as precision equipment work, line Started a frequency converter or welding machine work on precision instruments produce high harmonic interference, this time with a pointer table is more intuitive, while the digital table pop-up word a moment is 8, a moment is 0 trend can not see.
Reasons for no response to the measurement of capacitance with a multimeter
We know that the capacitor is made of two pieces of metal with an insulating plate, when the voltage between the two electrodes will have a charge. Therefore, in the measurement must be discharged before detection, multimeter measurement of capacitance unresponsive should have the following reasons
1, capacitor internal circuit breakage, capacity failure. This is still relatively common
2, the multimeter is damaged, the capacitance measurement gear can not be used. The main reason may be charged with the wrong voltage, resulting in damage to the internal components of the multimeter.
3, the wrong gear, may not pay attention and choose the wrong gear, or the jack is not inserted correctly, is also more common.
Multimeter measurement of capacitance does not respond, the reasons are: 1. capacitor failure, disconnection; 2. capacitance capacity is too small; 3. multimeter measurement of capacitance function is damaged or unavailable; 4. measurement method is not correct.
