Measurement of Alcohol, Extract and Original Gravity


BEER MONITOR is a variant of COMBITEC and allows measuring simultaneously alcohol and extract in the brewing process. The original gravity is automatically calculated and displayed by the sensor.

The instrument combines the functionality of both RHOTEC (density measurement) and SONATEC (sound velocity measurement) and is designed for applications requiring maximum sensitivity and highest accuracy. It is easy to operate and maintenance-free.

The density measurement is based on the oscillating U-tube principle. For sound velocity measurement a sound pulse is created by a sonic transmitter and detected by a sonic receiver. As a specific property of each liquid, the correlation between concentration and density resp. sound velocity 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.

Typical Technical Data

  • Alcohol Measurement Range

    0 - 12.5 vol. % ±0.02 vol. %

  • Extract Measurement Range

    I) ±1 ppb
    II) ±30 ppb

  • Original Gravity Measurement Range

    I) 0 - 4.2% O2
    II) 0 - 50% O2

  • Response Time


  • Pressure of Operation

    max. 16 bar

  • Temperature of Operation

    -13°F to 257°F (-25°C to +125°C) (Pt1000)

  • Material

    1.4404/1.4435/AISI 316L; Hastelloy; Tantalum; etc.

  • Input

    10 x digital (24 VDC) & 2 x analog (4 - 20 mA)

  • Output

    5 x digital (24 VDC) & 4 x analog (4 - 20 mA)

  • Profibus DP


  • Enclosure Rating


  • Power Supply

    24 VDC


  • Very accurate determination of alcohol, extract and original gravity
  • Patented compact design with local display available
  • Hygienic execution; various materials and flange connections