The Endress+Hauser Group

Media center

Endress+Hauser Events

Your career with Endress+Hauser

Support close to you

Servo tank gauging instrument
Proservo NMS81

High precision servo measurement for liquid level, interface and density

  • Proservo NMS81 ©Endress+Hauser
  • Proservo NMS81 ©Endress+Hauser

The intelligent tank gauge Proservo NMS81 is designed for high accuracy liquid level measurement in custody transfer and inventory control applications with NMi- and PTB-approvals. It meets the relevant requirements according to OIML R85 and API 3.1B. It fulfills the exact demands of tank inventory management and loss control and is optimized in regards of total cost saving and safe operation.


  • Hardware and software developed according to IEC 61508 up to SIL3 (in homogeneous redundancy) for high level of safety

  • Maximum reliability through accuracy up to ±0.4mm (± 0.02")

  • Developed according to international metrology recommendations such as OIML R85 and API MPMS

  • Local and country-specific certifications like NMi or PTB for custody transfer applications

  • Simplified installation and trouble-free operations due to easy connection to major DCS systems via open protocols

  • Measurement of interfaces between up to three liquid layers, tank bottom, spot, and profile densities

  • Superior corrosion resistance with 316L materials in the process

Field of application

For high accuracy custody transfer measurement in crude oil, gasoline, diesel, petrochemicals and chemicals.

  • Process connections: Flanges

  • Temperature: -200 to +200°C (-328 to +392°F)

  • Pressure: 0 to +25bar (0 to +362psi)

  • Maximum measuring range: 47m (154ft)

  • Accuracy: ±0.4mm (±0.02")

  • International explosion protection and custody transfer certificates, overfill prevention WHG, SIL

Features and specifications

Documents / Manuals / Software

Accessories / Spare parts


Endress+Hauser AG
Kägenstrasse 2 4153 Reinach BL Switzerland
Tel.: +41 61 715 7700
Fax: +41 61 715 2888
Send email

Related news

Online Tools