The Design Of White-light Interferometer And Its Application For Liquid Level And Absorption Coefficient Measurement

In this paper, the method of liquid level measurement with a high resolution is present. This method can measure continuously liquid with low viscosity coefficient. The white light interferometer was based on the Michelson interferometer and the technique is a convenient, high resolution, noncontact method. It can meet the need of small measurement range and high resolution simultaneously. The experimental results show that the resolution is ± 1.25 μm in the range of 86mm. Besides, the absorption coefficient of extracellular fluid was calculated by the liquid level and the transmission light intensity which were measured by changing the white light interferometer system. The result is consistent with the Beer-Lambert's law, and this method solve the problem about the light intensity when the light perforate extracellular fluid. This is the basis for studying the relationship between light and cell quantificationally.The design of the white light interferometer is analyzed from theories and experiments, including the designs of the driving electrocircuit and detected and magnify electrocircuit. Two driving electrocircuits is compared, one is fit the small power light source and the other is fit the large power. The result shows the former can used the manostat and limit current resistance, the latter can used negative feed-back amplifier to accomplish constant current driving.