RHOTEC is a highly precise density velocity sensor for determination of densities and concentrations (e. g. of ethanol, oils, fuels, acids or caustics). The sensor can be used for instance for phase detection.


The density sensor RHOTEC continuously measures the density of liquids according to the oscillating U-tube principle. The instrument is designed for applications requiring maximum sensitivity and highest accuracy. It is easy to operate and maintenance-free. For density measurement the liquid flows through a thin U-shaped tube inside the sensor. Using electromagnets, the tube is excited to oscillate at the resonant frequency. At the same time, an integrated reference oscillator measures the oscillation characteristics. Even the smallest changes in fluid density have an impact on the detected signal and are identified with highest precision. As a specific property of each liquid, the correlation between concentration and density can be described by a mathematical polynomial. With decades of experience and our own laboratory facilities, Centec know the polynomials for a large number of products. Any temperature drifts of the measured signal are automatically compensated for by an internal Pt1000 sensor. RHOTEC can display liquid density and solution concentration in various units.

European patent application: 1 439 438 B1

  • Most accurate technology to determine density and concentration
  • Patented compact design with local display available
  • Large variety of materials and flange connections
  • Hygienic execution and full CIP capability
  • Easy to operate and maintenance-free

Technical Data

Measuring Range 0 - 3 g/cm3
Accuracy ± 0,0001 g/cm3
Repeatability ± 0,00001 g/cm3
Response Time ≤ 1 s
Pressure of Operation max. 50 bar
Temperature of Operation - 25 - + 125 °C
Temperature Sensor Pt1000
Material 1.4404/1.4435/AISI 316L; Hastelloy; Tantalum; others on request
Connections thread 3/8”; others on request
Input Transmitter Version 6 x digital (24 VDC)
Output Transmitter Version 3 x digital (24 VDC) & 2 x analog (4 - 20 mA)
Profibus DP Transmitter Versionoption
Profibus DP Sensor (w/o local display) standard
Enclosure RatingIP65
Explosion Protection (ATEX) Ex II 2G EEx d IIC T6 option
Power Supply 24 VDC


Tel.: +49 6181 18 78 0
Fax: +49 6181 18 78 50


RHOTEC - Datasheet / Datenblatt
(0,77 MB, PDF, EN/DE)