A comparison of particle diagnostic systems

An experimental investigation was conducted to examine the particle sizing characteristics of four particle diagnostic systems (PDS): a fiber-optics array probe (FOS), two separate particle-sizing interferometers (PSI), and a backscattering particle-sizing system (BPS). Simulated icing clouds, produced in an icing research test cell, were used as the particle flow field for the investigation. An in-line holocamera was selected as the baseline device and was, therefore, used to calibrate each icing cloud. Each PDS was used to obtain particle size information for each simulated icing cloud. Typical examples of the results obtained with each PDS are presented as well as typical calibration results. The results obtained with each PDS are also compared to the calibration results. The comparisons show that the FOS is the only device tested that yields results comparable to the holocamera results. The particle number density of a simulated icing cloud is shown to be too large for obtaining accurate particle size data with an on-axis forward-scattering PSI. The data obtained with the BPS exhibit a monodisperse distribution and are inconsistent with the holographically obtained calibration data.