RHOTEC ALC-TAX is a variant of RHOTEC and allows measuring alcohol during the production, when alcohol content needs to be determined by a certified instrument for reasons of taxation.


The density sensor RHOTEC ALC-TAX continuously measures the content of alcohol. Meeting the requirements of PTB (Physikalisch Technische Bundesanstalt), the device is accepted and certified by German government authorities. 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 ALC-TAX can display liquid density and solution concentration in various units.

European patent application: 1 439 438 B1

  • Most accurate technology to determine alcohol content
  • Accepted and certified by German authorities, PTB-design type with calibration error 0,0001 g/cm³ for alcohol, alcohol-water-mixtures and water
  • In combination with different types of certified flow meters, the requirements of PTB and BfB (Federal Monopoly Administration for Spirits) are met
  • Patented compact design with local display available
  • 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 Range (acc. to official standards) 0 - 5 bar
Temperature Range (acc. to official standards) 5 - 40 °C
Temperature Sensor Pt1000
Material 1.4404/1.4435/AISI 316L; Hastelloy; Tantalum; others on request
Connections thread 3/8”; others on request
Output Transmitter Version 1 x analog (4 - 20 mA)
Profibus DP Transmitter Versionoption
Profibus DP Sensor (w/o local display) standard
Enclosure Rating IP65
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 ALC-TAX - Datasheet / Datenblatt
(0,78 MB, PDF, EN/DE)