摘要:

AbstractThis paper describes seven different methods of calibrating optical particle sizing instruments based on single particle scattering theory. The results presented were obtained from a Laser Doppler Anemometer (LDA) using two concentric probe volumes of different diameters and colours. Measurements of the Doppler signal frequency, amplitude and visibility can yield the absolute particle size and velocity of individual particles providing that the optics and processor are correctly designed and implemented.The requirements for signal processing without validation bias are discussed together with the use of a Doppler signal generator for testing the processor. Calibration of the system is then described using a scanning pinhole unit, calibration plate and aerosols of bronze spheres. The other techniques described are the use of glass spheres mounted on thin stalks, Berglund‐Lui monodisperse particle generator and latex spheres entrained in a recirculating cell. The discussion indicates the sizing range over which the above techniques are applicable. This covers a total size range from 1 micron to 1 millimetr

ISSN:0934-0866    

DOI:10.1002/ppsc.19870040132

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

摘要:

AbstractDouble pulse holography is, for experimental investigations, an extremely valuable means of measuring transport processes in disperse phases. This method allows the single or two dimensional frequency distributions of particle size, velocity, momentum and energy to be determined for each recorded sub‐collective, with the additional possibility of checking the existence of their correlation. Being an imaging method, the distributions of the particles in space can be displayed along with the instantaneous values of the concentration and particle flux density.A complete and very exact evaluation of the holographic images, coupled with the certainty of image pairing, is one of the prerequisites of a successful application. The best evaluation in this sense is, at present, produced by a semi‐automatic, interactive system in which the assessment of certain crucial factors is left to an operator.Although the effort incurred by such a total evaluation is by no means insignificant, it is justified by the profusion of information to be obtained.The present report explains the whole concept including a programme system with which the primary data is further processed and with which a variety of results may be called up and displa

ISSN:0934-0866    

DOI:10.1002/ppsc.19870040133

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

ISSN:0934-0866    

DOI:10.1002/ppsc.19870040134

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY

ISSN:0934-0866    

DOI:10.1002/ppsc.19870040101

出版商:WILEY‐VCH Verlag GmbH    

年代:1987

数据来源: WILEY