Summary of digital multimeter maintenance and care methods
Regarding the maintenance and maintenance methods of digital multimeters, the maintenance methods of digital multimeters include the sensing method, voltage measurement method, short circuit method, circuit breaking method and component measurement method, etc. There are three key points in the daily maintenance of digital multimeters.
During the use of the multimeter, certain malfunctions may occur due to its own operation and environmental problems, which will have a certain impact on the normal use of the user. Therefore, the maintenance and upkeep of the digital multimeter is indispensable.
How to maintain a digital multimeter
However, due to the multifactorial nature of its failures and the high randomness of problems encountered, there are not many rules to follow. We have compiled some repair experience accumulated in actual work for reference by colleagues in this profession.
When looking for faults, you should first look for the outside and then the inside, first the easy and then the difficult, break it into parts, and focus on breakthroughs.
Detection method of digital multimeter:
1. Feeling method
Use your senses to directly judge the cause of the fault. Through visual inspection, you can find such things as broken wires, desoldering, short circuits, broken fuse tubes, burned components, mechanical damage, lifted and broken copper foil on printed circuits, etc. ;You can touch the temperature rise of batteries, resistors, transistors, and integrated blocks, and refer to the circuit diagram to find out the cause of abnormal temperature rise.
In addition, you can also use your hands to check whether the components are loose, whether the integrated circuit pins are firmly inserted, and whether the transfer switch is stuck; you can hear and smell whether there are any strange sounds and smells.
2. Voltage measurement method
Measuring whether the working voltage of each key point is normal can help you quickly find the fault point. Such as measuring the working voltage and reference voltage of the A/D converter.
3. Short circuit method
The short circuit method is generally used in the methods of checking A/D converters mentioned above. This method is often used when repairing weak current and microelectric instruments.
4. Circuit breaking method
Disconnect the suspicious part from the whole machine or unit circuit. If the fault disappears, it means that the fault is in the disconnected circuit. This method is mainly suitable for situations where there is a short circuit in the circuit.
5. Component measurement method
When the fault has been narrowed down to one location or a few components, it can be measured online or offline. If necessary, replace it with a good component. If the fault disappears, it means the component is bad.
Daily maintenance of digital multimeter
The digital multimeter is a precision electronic instrument. Do not change the lines at will. Pay attention to the following points when using it:
1. Do not connect to a voltage higher than 1000V DC or higher than 700V AC RMS voltage.
2. Do not connect the voltage source when the function switch is in the Ω and position.
3. Please do not use this watch when the battery is not installed or the back cover is not tightened.
