4.1 Perfect optical performance UV1900 adopts new design of double beam ratio monitoring system with perfect optical properties. The high performance holographic blazed grating makes sure the low stray light for the instrument. 4.2 Comprehensive functions 4.2.1 Photometric measurement can measure the transmittance and absorbance of the wavelength. 4.2.2 Spectral measurement scans the graph of transmittance, absorbance, reflectivity and energy within the wavelength range, and deal with data of peak detection, derivative compute, graph compute and so on. 4.2.3 Quantitative measurement: setting the A-C curve by K-coefficient method and equation method of linear regression. 4.2.4 Dynamic measurement: operating the time scanning and data calculation of the transmittance and absorbance at any set wavelength. 4.2.5 Data output: the data and parameters files can be stored, and the measured results can be output by data files which fit the standard requires. 4.3 Advanced circuit control system The instrument has high stability and extremely low noise by the advanced design of circuit control system. 4.4 The injection chamber can be disassembled It has disassembled injection chamber with automatic four-connecting injection cells for changing different accessories according to userâ??s analytic needs. 4.5 Design of spacious and open light chamber is convenient to change the light source. 4.6 Stable and reliable performance The key components are imported. Adopted imported deuterium lamp and photocell make sure the instrument performance stable and reliable. 4.7 Powerful operating software The operating software in both Chinese and English is developed by windows. It supports special analysis functions of totally control the host which contain data collection (single-point measurement, multi-point measurement, spectral scanning, quantitative measurement and time scanning) and various of data processing. 4.7.1Standardizatiion, peak detection and area calculation. 4.7.2The graph can be zoomed in and out, parallel slid and T-A switched. 4.7.3 Quantitative measurement for Single wavelength. Methods of K-coefficient, single-point working curve, multi-point working curve, and operation of 1~3 function fittings. 4.7.4Method of excluding abnormal points in quantitative analysis. 4.7.5Calculation for curve coefficient 4.7.6Mass memory for scanned graphs, working curves and measured results. 4.7.7The measured reports are output in a standard file format. 4.7.8Any printer for choosing. 4.8 Large screen display. Six inches lattice backlit digital LCD has the distinguishability of 320*240.