Research of Spectrophotometer for Bio-Chemical Analyzer Based on Automatic Adjustment of the Integration Time of Linear CCD

The bio-chemical analyzer (BCA) is a kind of instrument which is used to measure some clinical or chemical targets in samples (blood). Since light source's energy is different and samples have different spectrum absorbance in different wavelength. Energy attenuation of ultraviolet (UV) wavelength is large; otherwise, The noise which exist in the electronic circuits and the astigmatism which exist in the ray-route system ,both of which will reduce the luminosity nicety in the UV wave-band. In this paper, Virtual Instrument(VI) technique and the method of software optimizing algorithm are used to enhance measurement veracity of the luminosity value, and the exposure time of linear CCD is auto-adjusted to expose separately for strong light and week light. From experiment results , we can obtain that the capability and signal to noise ratio (SNR) of the system are greatly improved , the spectrum range of spectrophotometer for BCA can reach 300~800 nm and the distinguish of wavelength is less than 10 nm.