HUDSON, Mass. — The battery portable, fast-responding, PPM2 hygrometer from Edgetech Instruments uses a fundamental principle and a diffusion barrier to measure trace water vapor in gases from 0.1-1,250 ppmv. Recalibration is not required under normal usage.

The PPM2 is a trace moisture analyzer for monitoring dew/frost point temperature or ppmv water vapor content in gases. It is configured to meet remote, spot sampling, or semi-permanent absolute humidity measurement requirements. Detectible range is from 0.1-1,250 ppmv water vapor. The PPM2 is ideally used for relatively clean, dry, inert gas measurement. Applications include air separation and purified gases, medical and pharmaceutical gases, and semiconductor manufacturing.

The PPM2 uses an electrolytic, phosphorus pentoxide sensor in combination with a protective, proprietary, semi-permeable diffusion membrane. The principle of operation applies Faraday’s Law of Electrolysis to determine the water vapor content by measuring the dissociation current needed to electrolyze the water molecules in a gas sample.

The PPM2 is packaged in an impact-resistant, waterproof, IP65 plastic enclosure. A USB  

bidirectional serial interface is standard as is a 115/230 Vac battery charger.