Need assistance? Call us: 1-800-663-4209
MDM300
Portable and Intrinsically Safe Advanced Dew-Point Hygrometer for Industrial Gas Applications
- Repeatedly fast measurements at low pressure from less than 15 minutes for T95 to -60 °C (-76 °F)
- Higher pressure measurements possible- up to 350 barg (5076 psig)
- Long battery life: up to 48 hours of typical use between charges
Product Overview
- Accuracy ± 1 °C (± 1.8 °F)
- Accuracy Detail ±1 °C from -60 to +20 °Cdp (-76 to +68 °Fdp), ±2 °C from -100 to -60 °Cdp (-148 to -76 °Fdp), ±0.2 °C (0.3 °F)
- Analog Input Note 4 to 20 mA external input selectable as either dew point, temperature or pressure
- Applications Air, Air Dryers, Air or Gasses, Clean Rooms, Compressor Control, Flow Measurement, Gases, HVAC, Mechanical Structures, Natural Gas Compressors, Oil and Gas, Pipeline Measurements, Plastic Extruders, Plastic Forming, Plastic Molding, Pneumatic Systems, Power Plants & Boilers, Product Quality Assurance, Steam, Temperature Maintenance, Water
- Battery life 24 hr
- Battery Size and Type NiMh
- Calibration Note For Spot Checks -70 to +20 °Cdp (-95 to +68 °Fdp), For Online Analysis -100 to -70 °Cdp (-148 to -95 °Fdp)
- Compliance Note ATEX/UKCA: II 1G Ex ia IIC T4 Ga (-20 °C to +50 °C) IECEx: Ex ia IIC T4 Ga (-20 °C to +50 °C) TR CU Ex: 0Ex ia IIC T4 Ga cQPSus: Class I, Division 1, Groups A B C D, T4 Class I, Zone 0, AEx/Ex ia IIC Ga T4 (-20 °C to +50 °C)
- Data Interface Bluetooth
- Data Interface Note (Wireless) BluetoothTM range up to 5 m (16 ft)
- Data Logging 8 MB for 5 to 60 s logging interval
- Display Type LCD
- Enclosure Material High Impact Polyamide with Steel Fiber
- Enclosure Ratings IP66, NEMA Type 4
- Flow Rate Note Flow across sensor: 0.2 to 0.5 Nl/min
- Materials, Wetted 316L Stainless Steel, Borosilicate, Ceramic, PTFE
- Measurement Resolution Better than 0.1 °Cdp (0.2 °Fdp)
- Operating Humidity 0 to 100% RH
- Operating Pressure, Max 35 MPa
- Process Connection Size 1/8 in
- Process Connection Type NPT Female
- Response Time T95 in ≤30 minutes to -60 °C (-76 °F) dew point
- Series ID MDM300
- Storage Temperature, Max 50 °C
- Storage Temperature, Min -20 °C
- Supply Voltage 4.8 Vdc
- Temperature Measurement Range -20 to 50 °C
- Weight 1.5 kg
Supported Applications
The MDM300 is a high-speed portable dew-point hygrometer built for rapid, repeatable spot-check measurements of dew point and moisture content in the field. Because it settles quickly and is easy to carry, it allows more measurements per working hour than comparable instruments, which makes it well suited to survey and maintenance work rather than fixed installation.
Typical applications include compressed air systems, natural gas and high-voltage switchgear quench gas. The instrument reads moisture in air, N₂, CO₂ and SF₂, and the MDM300-IS variant adds hydrogen (H₂) among its supported gases. Wetted parts of AISI 316L stainless steel, a PTFE seal, borosilicate glass and a ceramic sensor give broad chemical compatibility, and the intrinsically safe variant is certified for use in hazardous areas.
Operating Conditions & Performance
Measurement is by a Michell ceramic metal-oxide moisture sensor with a calibrated dew-point range of -100 to +20 °C dew point. Accuracy is ±1 °C from -60 to +20 °C dew point and ±2 °C from -100 to -60 °C dew point, with a temperature accuracy of ±0.2 °C. Display resolution is 0.1 for all dew-point derived units, with measurement resolution better than 0.1 °C dew point.
The instrument operates over an ambient range of -20 to +50 °C and up to a maximum operating pressure of 350 barg (5076 psig). It carries an IP66/NEMA 4 enclosure and is CE and UKCA marked, with ATEX, IECEx, FM and INMETRO certification available on the intrinsically safe models. Data logging provides 8 megabytes of memory with log intervals of up to 60 sec and up to 10,000 logs per file, and results can be transferred over Bluetooth. Power is from a NIMH 4.8V battery pack.
The housing is a steel fiber-loaded high-impact polyamide 6 case measuring 218 mm x 170 mm x 90 mm, and the process connection is 1/8" NPT female.
Configuration Options
The line splits into a standard instrument and an intrinsically safe (I.S.) instrument, and the practical differences follow from that hazardous-area certification:
- Certification — the MDM300-STD is the advanced portable hygrometer, the MDM300-IS adds ATEX, IECEx and FM certification, and the MDM300-IS-INMETRO further adds INMETRO certification for the Brazilian market.
- Battery endurance — the standard unit runs up to 48 hours of typical usage between charges, while the I.S. unit runs up to 24 hours; its intelligent charger is not certified for hazardous-area use.
- Response speed — typical response is T95 in ≤15 minutes to -60 °C dew point on the standard model and T95 in ≤30 minutes on the I.S. model.
All variants share the same ceramic metal-oxide sensor, calibrated range and 350 barg maximum operating pressure, so the choice is driven by the certification and endurance needed for the working environment.
Key Product Differences
The base-model lineup is defined by certification level:
- MDM300-STD — advanced portable hygrometer.
- MDM300-IS — advanced portable hygrometer with ATEX, IECEx and FM certification.
- MDM300-IS-INMETRO — advanced portable hygrometer with ATEX, IECEx, FM and INMETRO certification.
A broad accessory and spares program supports the instruments, including the MDM300-STD-BAG and MDM300-IS-BAG carry bags, the MDM300-CASE and hazardous-area MDM300-IS-CASE hard cases, Swagelok and Legris gas fittings, flexible tubing assemblies, and the EA2-TX external dew-point sensor with MDM-DP-SC02 cable. Service exchange and recalibration codes (13 points between -100 and +20 °C dew point) keep instruments traceably calibrated.