YSI EcoSense pH100A [606033] pH Meter w/Probe, 4m Cable and Carrying Case. The YSI pH100A 606033 is a waterproof portable pH, oxygen reduction potential (ORP)/mV, and temperature meter with manual temperature compensation, the capability for Automatic Temperature Compensation (ATC) , a multilevel LCD screen, an auto lock feature, and an Ingress Protection (IP) 67-rated housing. A pH meter is commonly used to measure the pH of substance such as water, food, beer, or wine in laboratory, industrial, and food applications. An ORP meter, also known as a redox potential tester, measures the oxidization or reduction capacity of a solution, and monitors chemical reactions and ion activity. The multilevel screen simultaneously shows the current measurement and the current temperature, and has onscreen tutorial messages for calibration and measurement. An auto lock feature for pH and mV determines and displays end point measurements. The meter has both manual temperature compensation and ATC for accurate readings in fluctuating temperatures. It has two-point automatic pH calibration with auto buffer recognition of 4.01, 7.00, and 10.01 or 4.00, 6.86, and 9.18. The offset recognition is + or - 90mV at pH 7.00 or 6.86 and the slope recognition is + or – 30 percent at pH 4.00, 4.01, 9.18, or 10.01. The housing is Ingress Protection (IP) 67-rated for protection against solid objects, including dust or liquids. The meter comes with a 1m (3'3) waterproof Y-cable with a combination pH electrode and temperature probe. One 9V battery provides up to 1000 hours of operation. The YSI pH100A also comes with a hard-sided carrying case.