Many electronic components are used in printed circuit boards, and different components are tested via different methods. The following introduce the test methods for photoresistors:
When detecting the photoresistor, set the multimeter to the Rx1k grade, connect the two test pens to the leads of the photoresistor, and then test according to the following method.
(1) Detection of dark resistance (protection from light). Covering the light-transmissive window of the photoresistor with black paper, adjust the multimeter’s gear switch to ohms grade, and then measure the resistance at both ends with the multimeter’s two test pens. If the pointer of the multimeter remains basically, resistance value is large or close to infinity indicates a better photoresist performance. If the resistance is small or close to zero, the photoresistor has broken down and cannot be used any more.
(2) Detection of light resistance (light transmission detection method). Align the light source with the light-transmitting window of the photoresistor, and use the two test pens of the multimeter to contact the two leads of the smoothing surface resistor. If the pointer of the multimeter has a large amplitude swing, the resistance is significantly reduced which indicates the device is normal. The smaller the better the resistance performance of the photoresistor. If the resistance is large or even infinite, which states that the internal open circuit of the photoresistor is damaged and cannot be used any more.
(3) Detection sensitivity (intermittent light detection method). Align the light-transmissive window of the photoresistor with the incident light source, and shake it with the black paper on the upper part of the light-transmitting window of the photoresistor to make it intermittently receive light. If the pointer of the multimeter swings left and right with the shaking of the black paper, then It is stated that the photoresistor is normal. If the multimeter pointer is always stopped at a certain position without swinging with the paper, it means that the photosensitive material of the photoresistor has been damaged and cannot be used any more.
The above is the detection method of the photoresistor, I hope to help you!
Pcb prototypes samples need to be aged prior to solderability testing. Because the solderable surface of the component or PCB circuit board that has just been produced is generally not problematic, it will deteriorate due to oxidation after being stored for a period of time. The test must conside...
During the manufacturing process of the circuit board, the temperature setting of the reflow oven determines the temperature resistance and soldering effect of the components. Sometimes it is not possible to debug as request when debugging the temperature curve. This is because for a specific pac...
The choice of wave soldering machine should be based on process requirements and process characteristics of PCB manufacturing. For example, if the the product output is large, it is necessary to consider the use of a long preheating zone; if the surface treatment of the PCB is OSP, a wave solderi...