HMF Mercury filled – HART – FM – SIL2-PLd



  • The HMF series of Gefran are pressure transmitters with HART communication protocol for use in high-temperature environments with explosive atmosphere presence.
  • The main characteristic of this series is the capability to read the temperature of the media up to 400°C.
  • The constructive principle is based on the hydraulic transmission of the pressure.
  • The fluid-filled system assures temperature stability. The physical measure is transformed into an electrical measure by means of strain gauge technology.

The transmitters have been designed and manufactured according to FM standards with the following types of protection and features:

  • Explosion-proof (XP) for Class I, Division 1, Groups A, B, C and D
  • Dust proof (DIP) for Classes II, III, Division 1, Groups E, F, and G
  • Indoor and outdoor areas classified as hazardous: Type 4X, IP67
  • Rated ambient temperature of T5 Ta = -20°C to +85°C, T6 Ta = -20°C to +60°C


  • Pressure ranges from: 0-17 to 0-1000bar/0-250 to 15000 psi
  • Extensimetric measurement principle
  • Accuracy: < ±0.25% FS (H); < ±0.5% FS (M)
  • FM approval for potentially explosive atmospheres
  • 1/2-20UNF, M18x1.5 standard threads, mounting flange ø 66.3mm (2.61")
  • Standard diaphragm is 15-5 PH stainless steel with GTP+ coating
  • 17-7 PH corrugated stainless steel diaphragm with GTP+ coating for ranges below 100 bar-1500 psi
  • Other diaphragm types available on request