Research and Design of Measuring Time Steady in TimeResolved Fluoroimmunoassay Instrument

The accuracy of timeresolved fluoroimmunoassay （TRFIA） instrument depends on that of the weak fluorescence signal detection, while the instability of the measuring time may result in that of intensity of fluorescence signal. Aiming at the three factors leading to the poor accuracy of the measuring time (the error in time basis, triggering error, quantization error), TX2108 crystal oscillator with temperature compensating is employed as the timebasis signal source to reduce the error in time basis; RISC-base high speed MCU and high reliable 74HC chips are utilized to ensure the simultaneous performance of the optical excitation and fluorescence signals such that the triggering error can be reduced; Dualvernier method is used to raise the measuring resolution for 3-times magnitude such that the quantization error is reduced. The experiment results show that, in the same measuring precision, measuring times are reduced from 1000 to 120.