Photodetector for the optical system of biochemical analyzer

　　In the measurement, the change of light signal must be converted into the change of electrical signal in order to make quantitative measurement. This device that uses the photoelectric effect to convert light energy into electrical energy is called a photodetector. Commonly used photodetectors in inspection instruments include photocells, phototubes, photomultiplier tubes, etc.

　　Photoelectric detectors for biochemical analyzers must meet the following three conditions:

　　● Photoelectric conversion must satisfy a constant functional relationship;

　　● Wide wavelength response range;

　　● High sensitivity, fast response speed, the generated electrical signal is easy to detect and amplify, and has low noise.

　　We chose silicon photocells as detectors. Silicon photocells have excellent performance, stable operation, small size, fast response speed, and no need for external bias voltage when working. They are "quiet" under stable light, do not increase noise, and can be input with low impedance to the amplifier, thereby reducing the induced noise and making the high-frequency loss on the shielding line negligible. These are very beneficial for improving the signal-to-noise ratio, reducing faults, and improving frequency response. In addition, the photoelectric transducer is simple and easy to use.