9 Ampere-hour meters; Battery testers; Electronic-based instruments for measuring environmental parameters including humidity, mold, bacteria, air quality and water quality; Electronic devices for measuring electric current; Radiation-measuring instruments; Scientific instrumentation for measuring intensity and wavelength of light ; Scientific instrumentation for measuring resistance, voltage, current, frequency and conductivity; Scientific instrumentation for measuring temperature, pressure, humidity, ph load, and force; Scientific measuring instruments, namely, conductivity meters; Voltmeters