K850 & KG850 - Ranges of 0-10% to 0-100% Volume - Analyzers utilizing Thermal Conductivity to accurately measure the changes of one constituent in binary or pseudobinary gas mixtures with a non-depleting katharometer sensor that requires no maintenance. A built-in sample pump means that samples can be drawn from low pressure sources or can be naturally aspirated. True portability is from sealed rechargeable batteries, which offer 6 hours continuous operation. Extended operation is possible by running the unit with the battery charger connected. The whole instrument is housed in a tough ABS case with a carrying handle that doubles as a variable-height tilt foot for bench use. A large, alphanumeric LCD shows measured values and also displays messages and prompts for the menu-driven configuration and calibration routines.