Measurement and Control System of Liquid Parameters

Measurement and Control System of Liquid Parameters is designed for continuous measurement of liquid level, temperature, volume and mass along with generation of analogue or digital output signal used as initial data of controlled medium state.

The system has a hierarchical distributed structure, which consists of two levels:

  • the first level includes up to six primary converters (sensors) of three configurations;
  • the second level includes a secondary converter which receives data from the first level and transmits it to external circuits through the RS-485 standard interface or using a direct current signal of 4–20 mA.
  • .

Depending on the operating conditions, the system configurations vary in the following characteristics:

  • number of measurement channels;
  • measurement range;
  • number of temperature control points (from 2 to 6);
  • operating pressure value of measured medium;
  • output signal;
  • primary converter design (coaxial, cable, two-leg);
  • power supply type.

Main specifications

Range of liquid level measurements 300–12 000 mm
Limit of admissible intrinsic error of level measurement ±2, ±4, ±6 mm
Limit of admissible intrinsic error of temperature measurement no more than 0.5 °С
Computational errors of indirect parameters:
measured liquid volume 0.5% of maximum tank capacity
measured liquid mass 0.75% of maximum available tank capacity
Output signals:
digital signal through the RS-485 interface (for transmitting of information on level, volume, temperature and mass of the measured liquid)
direct current of 4—20 mA with load resistance of no more than 500 Ω (for transmitting of information on level of the measured liquid)
Environmental parameters:
humidity up to 100% at 50 °С (without dewfall)
temperature –10 ÷ +55 °С
Power supply parameters:
alternating current voltage 220 V 50 Hz
direct current voltage 27 V