Electronic differential pressure for level measurement

Eliminates traditional mechanical issues resulting in greater process availability and reliability.

Differential pressure (dp) measurement is widely used to measure level in pressurized and vacuum tanks. However, traditional dp measurement using impulse lines and capillaries has its drawbacks in terms of accuracy, due to temperature deviations for example, and total cost of ownership.


  • High level of plant availability as no capillaries are require: reduction of temperature effects caused by solar radiation and changes in process temperature.

  • High level of process reliability: no plugging or condensation in impulse lines.

  • Significantly easier to install than capillary systems. Extended scope of application: insallation is independent of container geometry; adapter spacing of up to 45m for mouning sensors.

  • Optimized spare parts storage afford cost savings: instead of complete capillary systems of different lengths, only individual sensors have to be kept.

  • Fast and easy on-site commission via plain-text operation or via HART protocol to save time and money.

The application determines the correct sensor

The advantages of the sensors technologies with in the electronic dp system

  • The Ceraphire® ceramic cell (FMD71) is vacuum-resistant and best suited to corrosive and abrasive media. Based on capacitive sensor technology it offers additional safety with its self-monitoring function.

  • The silicon cell on the FMD72 offers temperature compensation for accurate measurement – even in applications with rapidly changing temperatures!

Reliable, safe and cost-effective sensor technology

Endress+Hauser’s new electronic differential pressure system, consisting of one transmitter with two sensors, offers proven pressure sensor technology in a new and innovative manner. The transmitter calculates the differential pressure from both sensors and transmits the level, volume or mass via 4...20 mA/HART as a standard 2-wire loop-powered device. This increases reliability and safety and reduces costs.

Put an end to incorrect measurements

The problems often encountered with conventional dp systems that use impulse lines include clogging, icing, leaks and condensation. Even those dp systems that use oil-filled capillaries face issues in applications with changing ambient temperatures. Electronic dp Deltabar FMD71 and FMD72 eliminate these problems - you not only benefit from precise measured values but also increased reliability and safety in your process.

Increased process safety

Safety risks are minimized with the new electronic differential pressure system architecture and design:

  • Elimination of tubing and connection leaks often encountered in traditional systems

  • Elimination of line condensation or evaporation events (dry/wet leg inconsistencies) and plugging events

  • Fully vacuum resistant Ceraphire® ceramic cells with the highest overload protection

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Electronic differential pressure Deltabar FMD72 ©Endress+Hauser
Electronic differential pressure Deltabar FMD72 ©Endress+Hauser