Flow and energy calculator

Energy calculator for heat, cold, steam and gas


The ERW 700 energy calculator is used for recording, processing, displaying, balancing and transferring volumes, mass and energy flows. In addition to the standard energy carriers water and steam, refrigerants, thermal oils and gases can also be processed. Almost any flow, temperature, pressure and density sensors or transmitters can be connected.

A high-precision and long-term stable measurement acquisition and processing is common to all variants. Type tests for heat, cold and “liquids other than water” by the metrological institutes PTB and NMI prove this. Numerous interfaces facilitate the transmission and processing of the measured and calculated values.

Technical data
Power supply 230 V AC or 24 V DC
Analog inputs 2-4
PT inputs 2
Digital inputs 2-6
Analog outputs 2-6C
Digital outputs 3-7
Interfaces M-Bus, RS232, RS485, Ethernet, Profibus DP
Protocols M-Bus,Pofibus DP, Modbus (ASCII, RTU, TCP/IP)


  • suitable for gases, liquids and vapours
  • can be combined with all common flow sensors
  • continuous calculation of density, enthalpy, compressibility, viscosity, Reynolds number, flow coefficient and expansion number
  • high-precision measured value acquisition with 24bit AD converters
  • short cycle time
  • full configuration on site also possible without PC
  • type approvals for heat, cold and liquids other than water
  • modular design
  • continuous further development of hardware and software
Special features
  • M-Bus, Modbus, Profibus
  • RS232, RS485, Ethernet
  • detachable display
  • display freely configurable
  • convenient PC software for configuration and service
  • bidirectional measurements
  • balancing in open systems (e.g. steam condensate)
  • ammonia (NH3) liquid and vaporous
  • optional 19″ cassette
  • data logger for error messages, min/max, key date, monthly and period values
  • numerous special functions
  • Warm measurement
  • Cold measurement
  • Steam measurement
  • Gas measurement