The Design And Implementation Of The Temperature Control System For A Chemiluminescence Immunoassay Instrument

Photomultiplier tube is used in electrochemiluminescence immunoassay techniqueto detect the weak light, thus the dark current noise or dark noise count is the mainlimitation of the precision and sensitivity of the light detection system. To break thislimitation, a temperature control system with dark current noise reducingphotomultiplier tube is proposed in this paper.The basic principles temperature control system is firstly illustrated in this paperfocusing on the principle, noise analysis, and the common cooling ways of thephotomultiplier tube. Then, by using DSP2812as the controller core, a driving circuit isdesigned to implement the PWM temperature control of the photomultiplier tube for thedriving features of TEC. Also, PID algorithm is adopted to precisely control thetemperature of the system by use of powerful calculation ability of DSP. On addition, aprogram of temperature display is compiled on PC to watch the temperature variationon the photomultiplier tube in real time. And a mechanical structure of temperaturecontrol system is designed and improved continuously based on the experiments to meetthe requirement of the performance. Finally, numerical experiment results demonstratethat the performance of instrument with temperature control system is significantlybetter than that of the instrument without temperature control system.