What does the meaning of a digital multimeter diode display greater than 1
When measuring diodes using the diode range of a digital multimeter, if the diode is normal, the digital multimeter displays "1" indicating a high reverse resistance of the diode. For silicon diodes, it displays a forward conduction voltage of 0.5V-0.7V. For germanium tubes, a forward conduction voltage of around 0.2-0.3V is displayed. When conducting forward, the red lead is connected to the positive pole of the diode, while the black lead is connected to the negative pole of the diode. Equal to "0" indicates a short circuit, indicating that the diode is faulty. In theory, the larger the reverse resistance of the diode, the better, while the smaller the forward resistance, the better.
Multimeters, also known as multiplexers, multimeters, triple meters, and multimeters, are indispensable measuring instruments in power electronics and other departments, generally aimed at measuring voltage, current, and resistance. Multimeters are divided into pointer multimeter and digital multimeter according to their display mode. It is a multifunctional and multi range measuring instrument. Generally, a multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance, audio level, etc. Some can also measure AC current, capacitance, inductance, and some parameters of semiconductors (such as β） Etc.
When setting a digital multimeter to the diode range to measure diodes, some data may appear. What does this data mean
Diode level measurement is used to measure the forward and reverse diode values of a diode. When the multimeter is in the diode level, the open circuit voltage of the V Ω hole and COM hole is about 2.8V. This voltage is applied to both ends of the diode. If it is in the forward direction, the diode will conduct and display a set of values, indicating that this is the forward diode value. If it is in the reverse direction, the multimeter will display "1" infinity, indicating that the diode is not conducting in the reverse direction. If the multimeter displays 000 in both measurements, it indicates diode breakdown. If the diode displays "1" in both measurements, it indicates an open circuit.
Why does the digital multimeter display a positive value of 410 when testing diodes in the diode range
When testing the diode range of a digital multimeter, sometimes the meter displays a positive value of 410, and there are three situations:
Due to the high dispersion of semiconductor materials themselves, most silicon diode tubes have a voltage drop of around 0.6V, while germanium diodes have a voltage drop of around 0.2V. However, it cannot be ruled out that some diode tubes have a voltage drop of around 0.4V (shown as 410).
The measured diode has been damaged (with soft breakdown). Some diodes are not completely damaged after a single breakdown, and when measured with a digital multimeter, the value is uncertain.
The battery of the digital multimeter is dead. When measuring the positive voltage drop deviation of the diode, it is necessary to check whether the meter battery is normal.
