1. Detection of electrical parameters of LED lamps: The electrical parameters mainly include forward, reverse voltage and reverse current, which are related to whether the LED lamps can work normally and are one of the basis for judging the basic performance of LED lamps. There are two types of electrical parameter measurement for LED lamps: that is, when the current is constant, the voltage parameter is tested; when the voltage is constant, the current parameter is tested.

  Forward Voltage. A forward current is applied to the LED lamp to be detected, and a voltage drop occurs across it. Adjust the power supply determined by the current value, and record the relevant reading on the DC voltmeter, which is the forward voltage of the LED lamp. According to relevant common sense, when the LED is conducting in the forward direction, the resistance is small, and it is more accurate to use the external method of the ammeter.

reverse current. Apply a reverse voltage to the LED lamp to be tested, adjust the regulated power supply, and the reading of the ammeter is the reverse current of the LED lamp to be tested. The same is true for measuring the forward voltage, because the resistance of the LED is relatively large when the LED is reversed, so the internal connection method of the ammeter is used.

2. Detection of thermal characteristics of LED lamps: The thermal characteristics of LEDs have an important impact on the optical and electrical characteristics of LEDs. Thermal resistance and junction temperature are the two main thermal characteristics of LEDs. Thermal resistance refers to the thermal resistance between the PN junction and the surface of the case, that is, the ratio of the temperature difference along the heat flow channel to the power dissipated on the channel, and the junction temperature refers to the temperature of the PN junction of the LED. The methods of measuring LED junction temperature and thermal resistance generally include: infrared micrograph method, spectroscopy method, electrical parameter method, photothermal resistance scanning method, etc. Using an infrared temperature measuring microscope or a micro thermocouple to measure the surface temperature of the LED chip as the junction temperature of the LED is not accurate enough.