Vasthi Engineers Moisture Analyzer Model VMA – 888 is heavy duty, industrial hygrometer systems for measurement of high pressure, process gases and vaporized liquids on natural gas platforms and terminals, petrochemical plants and industrial gas manufacturing facilities.




Vasthi moisture sensing technologies with sample conditioning system design engineering capabilities to provide a reliable and easy to operate, multi-channel on-line instrument for both flammable and non-flammable gases.

Vasthi Moisture Analyzer, This Model VMA-888 is a rugged on-line instrument tailored to customers’ specific application and technical requirements.

Video Measurements can be made across a wide range from -80 to +20°C dew point with an accuracy of ±1°C dew point and at process or pipeline pressures up to a maximum of 12 kg.


  • Natural gas production and processing
  • Pipeline drying
  • Offshore export pipeline natural gas
  • Transmission pipeline monitoring
  • Fiscal metering of gas
  • Gas storage facilities
  • Refinery recycle gas – reformer and plat former
  • LNG production processing and receiving terminals


  • Evaluation
  • Custom Designs
  • Calibration & Certification
  • Repair
  • Plant visiting
  • Sampling Systems



Analog output 4-20 mA for dew point
• Condensation insensitive
• Fast adjustment time
• Pressure resistant up to 350 bar(special version)
• R5485 RTU interface
• Higher resolution of the sensor signal history graphical data
• Sensor diagnosis on site with mobile device.
• Readable via Modbus:

Pressure dew point [°Ctd.]
Temperature [° C]
Rel. humidity [% RH]
Moisture content V / V [ppmV / V]

Technical Specifications

Measure range: -80…30°Ctd, -60, -30, -40, -30
Accuracy: ± 1°C to 50…-20°Ctd
± 2°C to -20…-50°Ctd
± 3°C to -50…-80°Ctd
Pressure range: -1…50 bar
special version up to 350 bar
Power supply: 24 VDC (16…30 VDC)
Protection class: IP 65
EMV: according to DIN EN 61326-1
Operating temp.: -20…70 °C
Connection: M12, 5-pole
PC connection Modbus-RTU interface (RS-485)
Analog output 4-20 mA = -80…20°Ctd
4…20 mA = -20…50°Ctd
FA 510: 4…20 mA (3-wire)
FA 515: 4…20 mA (2-wire)
Burden for analog output:<500
Screw-in thread: G 1/2“
optional: UNF 5/8“, NPT 1/2“
Dimensions: Ø 30 mm, length approx.130 mm
Via service software:Choose units % RH, °Ctd, g/m³, mg/m³,ppm V/V
Scaling change 4…20 mA