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212 Heat Calculator by Contrec

Contrec 212 Flow ComputerThe 212 Heat Calculator by Contrec has been designed to measure the energy consumed in hot water heating systems and chilled water cooling systems. The 212 is supplied complete with temperature probes and is able to interface with a wide range of flowmeters, including positive displacement and inferential water meters, magnetic flowmeters with pulse outputs, turbine and paddle wheel flowmeters.


Offering multilingual capability, datalogging and peak/off-peak operation are standard. The 212 in addition has four modes of operation covering heating and cooling ensure that it is flexible enough to meet all energy measurement applications.

The high accuracy of the 212 ensures that it meets European and International approvals for heat calculators.


The 212 can be supplied with two precision 4-wire Pt100 RTDs and has inbuilt correction for the non-linearity of the RTDs. For chilled water measurement where the temperature difference (Δt) is likely to be small, provision is made in the set-up program to zero out any offset between RTDs. The 212 is fully programmable and all set-up data and totals are stored in a non-volatile memory for a minimum of 10 years.



  • Complies with OIML R75 and EN1434 Standards
  • Multilingual Capability
  • Heating, Cooling and Air Conditioning
  • Built-in Density and Enthalpy Tables
  • Meter-Bus Interface or RS485 Communications
  • Metric or US Units
  • 4-Wire PT100 RTD Temperature Inputs
  • Fully Programmable
  • Calculates and Displays Volume, Energy, Temperatures and Peak Energy
  • Watertight to IP66 (Nema 4X)
  • High Accuracy
  • CE Compliant
  • 4-20mA Output Option 



Type: 7 digit LCD - 7 numberic digits and 11 alpha characters
Digits:  15.5mm high
Characters: 6mm hihg
Display Units: kWh, MWh, MJ, GJ, therm, BTU x 1000, tons x hours (refrigeration)
Maximum Thermal Power:  3000MW
Measurement Time:  0.5s
Accuracy: OIML R75 Class 4 and EN1434
Approvals:  Approved by Swiss Federal Office of Metrology to OIML Class 4
Interface: CE Compliance

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DC Power: 12 to 24Vdc @ 100mA maximum
AC Power: Supplied via power adaptor

Battery Version
Battery Type: 2 x Lithium battery packs
Battery Life:  5 years  

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Operating: 5 to 55°c
Storage: -20 to +70°c
Environmental Class:  EN1434 Classes A & C
Protection: IP66 (Nema 4X) watertight

Materials:  Polycarbonate and ABS

Mounting Options
Wall: Wall mount bracket

Panel: Mounting clips



Type: Frequency or pulse between 0.01Hz to 20KHz. Default low frequency cutoff is 0.25Hz
K-factor Range: Programmable in the range 0.0001 to 999,999.9 pulses per litre, m3, US gallon or ft3
Signal Type: Pulse, open collector, reed switch, proximity switch or coil
Location:  In either the return or feel lines
Type: 4-wire PT100 RTS's to IEC 751. 1/10 DIN
Location: 1 x Feed Line and 1 x Return Line
Linearisation: Built-in RTD linerarisation
Temp Range:  -10 to +220°c (1 to 200°c approved)
Temp Difference: 1 to 200K (1 to 199K approved)
Measurement Time: 3s
Cable Length:  <50m
Connection: G1/2B 


Outputs Display

Type: Open collector will sink up to 100mA, 30Vdc maximum
Width: 10ms
Function: Volume or Energy (scaled)
Frequency: 1 pulse every preset number of units of energy or volume total
Alarm (Not available iwht 4-20mA output)
Type: 2 solid state opto-isolated relays which will sink up to 100mA, 30Vdc maximum.
Function: High and low alarms individually programmable as unsigned values for flow rate, energy flow rate, feed tempertarue, return temperature or temperature difference.
4020mA Output Option
Function: Volumetric flow rate, energy flow rate, feed or return temperature, Δt
Accuracy: 0.1%
Span: Programmable
Load: Maximum of 300 ohms at 12v
Type: Conforms to CEN/TC176 meter bus standard
Protocol: ICE 870-5
 Data Transmitted: All data calculated can be transmitted
Baud Rate: 300 to 9600 baud
Parity: Odd, even or more
Stop Bits: One or two
Bus Address:  Programmable for multiple instuments on the same bus
Protocol: Modbus RTU
IMPORTANT: Specifications are subject to change without notice


212 Heat Calculator Dimensions by Contrec