Acoustic separation units; Anemometers; Carbon dioxide detectors; Carbon monoxide detectors; Circuit testers; Electrotechnical vibration meters; Infrared detection apparatus; Insulation resistance meters; Level gauges; Magnetic object detectors; Magnetometers; Metal detectors; Passive infrared detectors; Photometers; Radiation detectors; Resistance measuring instruments; Sound level meters; Temperature indicator labels, not for medical purposes; Voltage testers