Malvern Instruments, Inc. Spray Dispersion Spray Measurement

The versatility of the Mastersizer S is extended by its ability to measure droplet size as well as dry powders, wet suspensions and emulsions. The Mastersizer S detectors acquire light scattering data with an acquisition time of just 2 microseconds for each set of data. Consequently, as well as being very effective in detecting subtle changes in samples in real time, it is also very suitable for the measurement of sprays - particularly transient sprays such as metered dose inhalers and dry powder inhalers. A capability is provided to enable up to 100 individual "time slices" to be obtained from a single transient spray burst. Accessories provided to support spray measurements include an aerosol mounting unit to hold a wide variety of aerosol cans. An important aspect of spray measurement is the detection of the onset of a spray so that measurement can commence. It is also important for the system to be able to detect when the spray pulse has finished so that only meaningful data is captured. This is achieved by monitoring the obscuration of the laser beam of the sizer and setting a level of obscuration above which measurement will be triggered and below which measurement will cease.