Gas and liquid flow and temperature sensors; laser velocimetry units and parts therefor; optical components for laser velocimetry units; lasers; signal processors, computers; computer interface units and computer programs for use with gas or liquid flow measurement apparatus, namely, for collecting, processing, analyzing, storing, and presenting data from gas or liquid flow measuring instruments; preamplifiers; polarization axis finders; frequency shifters; hot wire and hot film anemometers; anemometry instruments and parts therefor; computer programs and interface units for use with anemometers, namely, for collecting, processing, analyzing, storing, and presenting data from anemometers and anemometry instruments; anemometer probes and sensors; manometers; gas flow and velocity test instruments; mass flow transducers; air velocity transducers, signal conditioners, air velocity meters; air velocity meter calibrators; wind velocity sensors; intelligent flow analyzers featuring microchips, for measuring flow rate and accumulation of liquids and gases; air pollution measuring and/or control instruments; aerosol neutralizers; condensation nucleus counters; electrical classifiers; electrostatic aerosol samplers; isokinetic dust samplers; electronic respirable aerosol mass monitors; particle impactors; computer programs and interface units for use with particle technology instruments, namely, for collecting, processing, analyzing, storing, and presenting data from instruments measuring particle size and/or concentration; measurement instruments for use in determining aerodynamic particle size; optical particle counters; differential mobility particle size analyzers; fume hood controllers; monitors for measuring the velocity of particles moving in a media; surface motion monitors; room pressure sensors; room pressure controllers; wind tunnels; flow calibrators; mass flow meters; ventilator test instruments; condensation particle counters; surface area monitors; lung deposition monitors, namely, an aerosol characterization device used to infer inhaled particulate uprate; mass flow meters to measure air flow in exposure monitoring applications; electronic instrumentation used in industrial hygiene and occupational exposure monitoring applications; in situ particle sizing instruments; phase doppler particle analyzers; planar laser induced fluorescent instruments; microscale particle image velocimetry instruments; multi-phase flow measurement instruments; velocity measurement devices; laser doppler velocimeters; nanoparticle/macromolecule generator