scientific and laboratory instruments for particle size distribution measuring, particle counting, zeta potential measuring, electrophoretic mobility measuring, particle mobility measuring, environmental monitoring (temperature and humidity), pH measuring, producing zimm plots to determine the molecular weight of polymers, namely, air and liquid particle counters, photo correlation spectroscopy instruments, micro electrophoresis measuring instruments, acoustic spectroscopy instruments, laser diffraction measuring instruments; apparatus for preparing samples, suspensions, sprays, and emulsions of particles for use with any of the aforesaid goods, namely, sample dispersion units, stirred cells, autosamplers, dry powder feeders, dispensers, auto titrators, nebulizers, ultrasonic baths, and temperature controllers; computers and microprocessors, computer printers, computer software for controlling and operating all of the aforesaid goods; machine readable data carriers, namely, floppy discs, CD-ROMs, optical discs, magnetic tapes, all for use with the foregoing goods