How to use a line check multimeter
1. Under the charged condition, measure the voltage at the key point or the power saving voltage, and judge whether the circuit is normal or not according to the height of the voltage or not;
2, with power, measure the key point or section current, according to the size of the current or not to determine whether the circuit is normal;
3, under power failure, measure the resistance of the circuit and components, pass or fail to determine whether the circuit is normal (short circuit, open circuit, etc.).
Multimeter to check electrical faults, generally only two gears, one is the voltage gear (including AC and DC voltage gear) another is the ohm.
If the equipment does not work, your first thought is whether the equipment voltage is normal, you need to use the multimeter voltage file (select AC voltage file or DC voltage file, depending on whether your equipment is AC equipment or DC equipment) to measure. If the control circuit or secondary circuit disconnection, in the event that you are familiar with the schematic diagram, you also have to use the voltage file to measure the voltage is normal, if you determine that the voltage should not be there instead of there, there should be instead of there, it means that there is a disconnection or poor contact phenomenon. In order to be more certain whether the place there is a problem, then you also have to disconnect the power supply of the equipment, the ohm file of the multimeter to determine whether the place has been disconnected, in order to troubleshoot. Roughly so, mainly rely on your familiarity with the equipment, the accumulation of experience in the work. There are still any questions, welcome to ask.
1. How to record intermittent faults with a multimeter.
Use the multimeter min/max/average recording mode, select the appropriate power level (AC voltage, DC voltage, resistance, AC current, DC current and frequency) according to the measurement item, and make sure that the test circuit is connected before activating the min/max/average function, otherwise the minimum reading will always be the ambient value before the test line is connected. This will affect the analysis of the recorded data after the recording time has elapsed. j Activating the min/search max/average recording mode will indicate the maximum reading on the multimeter display and will sound a beep when a new maximum or minimum value is detected.
The advantage of this is that you can leave the digital multimeter in place to take measurements and concentrate on other tasks while you ensure that it is not tampered with and does not pose a safety hazard to anyone. At any time during the recording cycle, you can view the saved readings or pause the recording mode without deleting the saved readings.
2. How multimeters continuously record intermittent faults: The multimeters have a minimum/ minimum recording mode and a minimum/ minimum recording mode.
Some multimeters not only have a min/max/average recording function, but also combine this function with another function called AutoHOLD2 and a larger memory to form an EventLogging function. The AutoHOLD function senses when the measurement signal becomes unstable and when it stabilizes again. By using the auto hold function to trigger the start and stop of the min/max logging function, the digital multimeter is not limited to detecting faults that produce minimum or maximum values.
If the multimeter has an infrared RS232 interface, the continuous recording function will be even more powerful, and can become a simple event collector to transfer the data collected by its multimeter to a computer. Using a computer, each stable and unstable event can be analyzed in detail. You can view not only the minimum and maximum values within each stable and unstable cycle, but also the start and end times of each cycle. The average value of each cycle is also recorded. At the same time, you can dynamically detect the trend graph of voltage or current changes.
3. How to mark the recording time of the multimeter.
The time at which the minimum and maximum values are detected is very useful information for determining the cause of intermittent faults. A digital multimeter in min/max/average recording mode can store the amount of time between the start of recording and the saving of a new minimum, maximum or average value. Thus, each saved minimum, maximum and average value has a corresponding "time stamp".
Nowadays, digital multimeters with digital acquisition or storage functions have the same bandwidth recording function through the computer or its own memory. If the digital multimeter has a min/max/average recording mode function arrow, and paper tape recorder, the digital multimeter also in a certain interval reading harness input readings. However, unlike paper tape recorders that save individual readings, the readings are compared to previously saved readings to determine if the value is higher than the previous maximum or lower than the previous minimum. jIf so, the new reading will be used to replace the value originally saved in the high or low reading registers. After a period of logging, you can call up the values clamored in these registers for display to see the maximum and minimum values during the logging time.
