The multi-wavelength liquid signature analyzer (MWLSA) is used to analyze the characteristics of liquid. It adopts two kinds of transmitter diodes with different peak wavelengths as the light sources of the system. With MWLSA not only the light intensity signal reflecting the optical characteristic of the sample liquid under different wavelengths can be obtained, but also the volume and outline information of the corresponding liquid drop are acquirable. The application of the multi-wavelength light sources makes it possible for us to get more information about the liquid sample, which
enriches the function of the liquid signature analyzer and improves its discrimination ability of different liquids so as to have more application fields.
An on-line operation of micro-spectrometer and liquid drop analyzer is proposed in this paper. Comparing with a full spectral range spectrometer system, a micro-spectrometer has narrow spectral range that results in its inefficiency or inability in qualitative analysis of a mixed liquid since more than one function group of the mixed liquid might cause a peak or valley in the spectrogram at almost the same wavelength. A liquid drop analyzer (LDA) is an instrument that detects the characters of a liquid by monitoring its drop forming process. The LDA gives a fingerprint that is unique for certain liquid due to its specific chemical, physical and mechanical characters. An approach of combining micro-spectrometer with a fiber drop analyzer, by which a virtual 3D liquid fingerprint is formed, is described and it functions like a full range spectrum. The signals obtained from the micro-spectrometer and liquid drop analyzer, the method of on-line operation and database setting up, the experimental device and test results are described and discussed in the paper.
An optical liquid drop sensor(OLDS) which can be used to distinguish different liquids is presented in this paper. The main block ofthis system are a light path and a drop-forming head sensor. We can gain three kinds ofiniormation about the liquid to be measured with this OLDS system. That is optical signal representing light intensity information, electrical signal revealing volume information ofthe liquid drop and spectral signal displaying ingredient information of the liquid individually. Colligate this three kinds of information and after data-processing the fingerprint of the measured liquid can be derived. Due to different characteristics of various liquids, the fingerprint of one liquid differs from that of others. This difference has been proved through experiment. Thus the OLDS is valuable for the discrimination of different liquids and the measurement ofthe liquid's parameters.