Anemometers; Hygrometers; Illuminometers; Air analysis apparatus; Alarms for the detection of inflammable gases; Atmospheric oxygen monitors; Carbon dioxide detectors; Carbon monoxide detectors; Digital multimeters; Electronic testing equipment, namely, sound level meters; Flue gas analyzers; Gas testing instruments; Magnets for industrial purposes; Measuring apparatus, namely, clamp meters for measuring electricity; Water testing instrumentation for monitoring and detecting contamination