The Oakton WD-35433-00 CD 650 conductivity/dissolved oxygen meter is a multi-parameter, handheld, waterproof, and dustproof meter, including kit. The meter measures conductivity, dissolved oxygen (DO), Total Dissolved Solids (TDS), temperature, salinity and resistivity within a substance, and is commonly used for waste water and salt water testing. This meter features automatic temperature compensation (ATC), with push-button calibration up to six points each for pH and conductivity, and three points for DO. It also has auto-buffer options and recognition, for ease of use. It has a large, backlit LCD screen to provide ease of viewing, and to display indicators. The meter has an adjustable, calibration-due alarm for performance. It stores up to 500 data sets, and has infrared, IrDA-wireless technology, for data communication. The meter has a built-in, real time clock with time and date stamping, and set-point alarms. It comes with an electrode status indicator and password protection. The meter has a conductivity range of 0 to 500.00 mS, resolution 0.01, 0.1 &muS; 0.001, 0.01, 0.1 mS, accuracy + or - 1.0 percent full-scale. Temperature range -10.0 to 110.0 degrees C (14.0 to 230.0 degrees F), resolution 0.1 degree C (0.1 degree F), and accuracy + or - 0.5 degrees C (+ or - 0.9 degrees F). DO range 0.00 to 90.00 mg/L (ppm), 0.0 to 600.0 percent, resolution 0.01 mg/L (ppm), 0.1 percent, accuracy + or - 2 mg/L; + or - 2%. TDS range is 0 to 500 ppt, + or - 0.05% full-scale (FS), range + or - 1% FS. Salinity 0 to 80 ppt. Resistivity 0 to 20.00 MO. Its dimensions are 7.25(l) x 3.25(w) x 2.25(h) inches, and it weighs 1.0 lb (0.45 kg). The meter has the ability to store up to 500 data sets in memory, until information can be communicated. Time and date stamping meets Good Laboratory Practice (GLP) standards, and the meter is Ingress Protection (IP) 67-rated, for protection against solid objects or liquids. The meter can be used with four 1.5 V AA batteries (not included), or a universal AC adapter (sold separately).