Design of Optical Energy Detection System for Atomic Absorption Spectrophotometer

An energy acquisition system is designed for the detection of atomic absorption spectrophotometer. Light energy detection is performed by photomultiplier tube which converts light energy signal from element lamp into pulsating weak voltage signal The secondary amplification circuit, filter circuit and zero adjustment circuit are designed to amplify the weak pulse voltage signal into DC voltage signal, so as to improve the anti-interference in signal transmission. The operational amplifier in the secondary amplifier circuit will introduce offset voltage, and the zero adjustment circuit is required to suppress the offset voltage; A high-precision AD converter is used for analog-to-digital conversion, and the corresponding filtering processing is carried out to obtain a high-precision energy signal. The practical application results show that the system design has the advantages of high precision, low signal-to-noise ratio and good real-time performance.