YSI Pro20 [603171] Dissolved Oxygen Meter w/4 m Cable, Polarographic DO Sensor & Carrying Case. Dissolved Oxygen Meter provides everything needed in a handheld dissolved oxygen meter. It is a rugged, reliable instrument that is easy to operate while featuring user-replaceable sensors and cables as well as the convenient One Touch Cal feature which makes the Pro20 extremely user friendly. The Pro20 is a true field instrument. Meeting IP-67 specifications while using military spec connectors and a rubber over-molded case, the YSI Pro20 Dissolved Oxygen Meter is designed for the toughest conditions. Choose from 7 Pro20 kits. Kits include everything from lab to field (or both) along with DO probe choices. Available sensors are EPA approved for wastewater compliance reporting of BOD, CBOD, and DO. Readings are shown on a graphic, backlit display. The YSI Pro20 Dissolved Oxygen Meter also records and stores up to 50 data sets. Dissolved oxygen readings can be either percent saturation (with a range from 0 to 500%) or mg/L (with a range of 0 to 50mg/L). Accuracies of up to ±2% are reached by incorporating an internal barometer. Fast response times with the Polarographic or Galvanic sensor allows you to complete your sampling routine quickly. The long life of the Polarographic sensor saves time and money and reduces your overall cost. The Galvanic sensor enables you to start sampling immediately without a warm-up period. Either sensor you choose for the field will give you accurate, quality data.