Detection method of infrared emission tube: after power supply of 850nm emission tube, the red explosion point can be directly seen in a dark environment. After the 940nm transmitting tube is powered on, you can see small red dots when you check it with your mobile camera in a dark environment.
Detection method of infrared receiving tube:
① Use the rx1k gear of the multimeter to measure the forward and reverse resistance of the infrared receiving diode. When the forward resistance is about 3-4k Ω and the reverse resistance is more than 5ook Ω, it indicates that the tube under test is good. If the forward and reverse resistance of the tube under test are both zero or infinite, it indicates that the infrared diode under test has been broken down or open circuit and cannot be used.
② Use the diode gear of the multimeter to measure the forward voltage of the infrared receiving diode. When the forward voltage is about 0.8-1.5v, and the reverse voltage cannot be displayed, it indicates that the tested tube is good. If the positive and negative voltage values of the tested tube are 0 or the positive voltage is infinite, it indicates that the infrared receiving diode has been broken down or open circuit.