High-Speed Advanced Technology Dew-Point Hygrometer

July 10, 2009
Michell Instruments has developed an all new high-speed dew-point portable Hygrometer for fast and accurate moisture content measurements in the field.  Based on Michell’s well-proven ceramic sensor technology, dew points to -95ºF can be reached in less than 10 minutes with an accuracy of better than ±1.8ºF. By avoiding the use of desiccant, continuous high speed operation of 6 measurements per hour is achieved. Operating range is -150ºF to +70ºF.  Housed within a rugged steel fiber-loaded polyamide case with NEMA 4 protection and weighing less than 3 lbs, the MDM300 features logging capabilities with Bluetooth wireless download of data. The rechargeable NiMH battery provides more than 48 hours continuous operation, with a rapid 20 minute recharge to further enhance the efficiency of use.  The MDM300 standard instrument is completely self-contained including a fixed orifice sample system for low pressures. Higher pressures up to 6000psi can be accommodated with a range of configurable external sampling systems and remote transmitters ideal for use in natural gas or other demanding processes. * Measurement Technology Michell ceramic sensor * Accuracy ± 1.8°F (± 1°C) from -75 to +70°F (-60 to +20°C) dew point ± 3.6°F (± 2°C ) from -150 to -75°C (-100 to -60°C) dew point ± 0.36°F (± 0.2°C) temperature * Measurement Range Calibrated -148/+68°F (-100/+20°C) dew point Readings to +85°F (+30°C) dew point Readings to +85°F (+30°C) dew point * Measurement Units °F, °C, K dew point ppmv, ppmw for air, N2, H2, C * Gas temperature: %RH, gm-3, gkg-1 * Option: active pressure (psi, bar, MPa, KPa) * Resolution (display) 0.1 for all dew-point derived units and autoranging where appropriate, e.g. ppm * Resolution (measurement) 0.01°F (0.01°C) dew point * Typical Response Speed T95 in ?10 minutes to -95°F (-70°C) * Measurement System Repeatability Better than 0.18°F (0.1°C) * Measurement System Stability 0.18°F (0.1°C) * Measurement System Hysteresis 0.09°F (0.05°C) Electrical input/output * Auxiliary Inputs 4-20mA loop-powered external input selectable as either dew point, temperature or pressure * Battery Type NiMH 4.8V * Battery Operating Life More than 48 hours of typical usage between charges * Battery Accessibility Internally mounted * Battery Charger Intelligent charger (supplied) Operating conditions * Operating Pressure Range 6000psi max with external sensor/sampling system * Operating Environment Outdoors 0 to +100% RH condensing * Operating Temperature -5 to + 120°F (-20 to +50°C) * Storage/ Transport Temperature -40 to +160°F (-40 to +70°C) Mechanical specification * Display Blue LCD graphical display * Enclosure Type Steel fiber-loaded high-impact polyamide 6 * Enclosure Ingress Protection NEMA 4 (IP66) * Gas Connections 1/8" NPT female (other options available) * Flow Across Sensor 0.4 to 4.0 ft3/hr * Filters 50 micron stainless steel sinter in the inlet port (other porosities available) * Gas Wetted Materials AISI 316L stainless steel * Outline Dimensions 8.6in. x 6.7 in. x 3.6 in. (218mm x 170mm x 90mm) * Weight 2.9 lbs (1.3 kg)