The Michell Instruments MDM300-IS intrinsically safe hygrometer is lightweight and portable, offering rapid spot-check measurements of dew point or moisture content in many applications, including compressed air, natural gas and high voltage switchgear quench gas. It is ATEX, IECEx, FM, and INMETRO certified for use in hazardous areas .

The instrument is contained within a steel fiber-loaded high-impact polyamide 6 case, sealed to IP66/NEMA4 standard and powered by an internally mounted Nickel Metal Hydride (NiMH) battery designed to typically provide 24 hours continuous use between charges . It is fitted with an internally mounted ceramic sensor enhanced for quicker response to dew points as dry as -75°Cdp.

The MDM300-IS features a graphical display, data logging capability, Bluetooth communication for trouble-free data download, and an external sensor interface for connection to a Michell Easidew I.S. transmitter. It includes a built-in on-screen calibration routine and has a maximum operating pressure of 350 barg (5076 psig). Continuous battery charge status indication is provided, with additional battery status information via icon, warning beep, and shutdown mode .

Key Features

• Intrinsically safe: ATEX, IECEx, FM, INMETRO certified
• Measurement range: -100 to 20°C (-148 to 68°F)
• Accuracy: ±1°C from -60 to 20°C, ±2°C below -60°C
• Response time: T95 ≤30 minutes
• High pressure capability: 35 MPa (350 barg / 5076 psig)
• Battery life: 24 hours typical
• Ceramic sensor with enhanced response to -75°Cdp
• Bluetooth communication for data download
• External sensor interface for Easidew I.S. transmitter
• Graphical display with on-screen calibration
• Data logging capability
• IP66 and NEMA 4 rated

Applications

• Hazardous area moisture spot-checking
• Compressed air systems in Zone 0 areas
• Natural gas processing
• Petrochemical plants
• High voltage switchgear gas monitoring