ABSTRACT
It's important to decrease the influence of hash in the optical measurement .We can use modulating method to improve the ability of resisting the interference.
The intensity of the signal that want to be measured is turned to be variational in periodic by through the modulating unit, entering the incident split of spectrometer with frequency f. Although the hash can enter the incident split at the same time, the circuit of selecting the frequency can only select the useful signal with frequency f. Thus the resisting the interference will come true.
