Ph meter, conductivity meter, tds meters, orp meter, pna meter, salt meter,tachometer,herm...
Water Quality Testing(monitoring) Instrument: PH meter, conductivity meter, TDS meters, ORP meter; pNa meter, salt meter; rotary speed measurement of the machinery manufacturing equipment: Many functions tachometer; air quality testing instrument: thermometer, hygrometer; Others: Refractometer, Water pump.