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Single stream Flow & Energy Computer

for water and saturated / superheated steam

Product description

The C581 flow and energy computer measures the actual flow, temperature and pressure and uses the IAPWS determinations to calculate the energy, mass and volumetric flow. The linearization enhances accuracy in any flow range. The large logging register contains all measured and calculated values. The robust IP66/67, Type4X aluminum field enclosure, withstands extreme weather and industrial conditions.

Our proven experience with instrumentation, international requirements and the focus on user-friendly operation are combined in the most robust, accurate and easy-to-use field mount Flow & Energy Computer on the market.

  • Robust IP66/67, Type4X aluminium field enclosure, withstands extreme weather and industrial conditions.
  • Large, versatile display with bright backlight, all info at a glance.
  • Easy-to-operate with 6 rugged industrial silicone buttons.
  • User-friendly operation and configuration via the keypad and display or with the free available configuration software.


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  • Displays calculated mass flow, volumetric flow and power at actual conditions.
  • Calculates totalized values for volume, mass and energy.
  • Determines density and enthalpy according to IAPWS.
  • Main screen with custom selectable order of measured and calculated variables.
  • Data logging of process parameters and calculated values.
  • 11 linearization points per input, for all inputs.
  • Ability to process various flow inputs: pulse (pending), (stacked) differential pressure or other 4 - 20mA signals.
  • Ambient temp.: -40°C to +55/+70 °C (-40°F to +131/+158°F).
  • Bright backlight for good readability during day and night.
  • Multiple languages supported.
  • Large graphical user interface with large digits.


  • For industrial environments, measuring water, superheated and saturated steam at heat exchangers, boilers, condensers and coolers.
  • For single or stacked differential pressure based flowmeters or averaging systems.
  • Extreme weather and industrial conditions like rain, snow, sandy deserts, salty atmospheres and temperatures between -40°C up to +70°C (-40°F up to 158°F).

Product specifications

  • Signal Inputs

    • Flowmeter Inputs

      • One HF pulse input (pending): NAMUR, Coil, PNP, NPN, Reed sensor or active input.
      • One to three analog inputs: 4 - 20mA active or passive. Also suitable for 2 or 3 stacked dP sensors.
    • Temperature Inputs

      • One Pt100, Pt500 (2- or 3-wire) or 4-20 mA (active/passive) input.
    • Pressure Inputs

      • One analog input: 4 - 20mA active or passive input.
    • Status Inputs

      • Two configurable inputs for e.g. external alarms.
  • Signal Outputs

    • Pulse outputs

      • Function: Two configurable pulse outputs, selectable from a list of calculated values. Frequency max. 2kHz.
      • Type: Two passive transistor outputs.
    • Alarm outputs

      • Function: Configurable for various errors or warning, selectable from a list of events, measured and calculated values.
      • Type: Two passive transistor outputs and two relay outputs.
    • Analog outputs

      • Function: Re-transmitting analog values, selectable from a list of calculated values.
      • Type: One or two configurable active / passive isolated 4 – 20mA outputs.
  • Supply

    • Power Supply

      • 16 – 27V DC
      • 100 – 230V AC
    • Sensor Supply

      • Analog inputs: >20V DC when active.
      • Pulse inputs: 5.4 – 8.2 – 12 – 22V DC
  • Hazardous Area

    • Non-Sparking, Zone 2

      • Pending.
  • Communication

      • Function: Reading display info, read/write configuration settings, data log extraction, firmware uploads (via USB only).
      • Protocol: Modbus RTU.
      • Interface: USB, RS232 and RS485 2-wire.

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