The Characteristic Parameters Of Light Scattering Particle Concentration Measurement Instrument Calibration Method

In order to realize measurement of aerosol mass concentration in real time byconcentration measuring instrument, the calibration of two characteristic parametersin the method is studied firstly. Through the measurement of suspended particulatematter sample, two characteristic parameters(equivalent parameter and sensitivitycoefficient) is obtained by the non-linear regression to Gauss-Newton method, therelation of the stability of characteristic parameter and concentration measuringinstrument range is further analyzed. The variety law of characteristic parameter isalso analyzed by minimization method, a method of equivalent parameter andsensitivity coefficient calibration is put forward, and it is used to calibrate theparameter of theory sample. It has been shown by experimentation that themeasurement relative error is lower than 10% between concentration measuringinstrument and SIDEPAK AM510 within lower than 5 mg/m~3. The propose ofcharacteristic parameter calibration method is also of great significance for onlinemeasurement realization of concentration measuring instrument.Secondly, the cost of concentration measuring instrument which contains 2048voltage channels is too high, so the voltage channel optimization problem is discussed.First the influence that the number of voltage channel exerts on measurementaccuracy and stability under uniformity partition is studied. Then the optimization ofvoltage channel division way is realized according to the characteristic of particlescattering signal voltage scope distribution, geometric proportion interval voltagechannel division way is used, the channel voltage interval is small in the low voltagetip, and remarkably increases in the high voltage tip. The result indicates thatnumerical value of mass concentration can attain measurement precision which is tall,and the relatively error of concentration measuring instrument and SIDEPAK AM510is less than percent of ten using four voltage channels. The conclusion offersacademic guidance for the design of particle counter's circuit.