RIKEN KEIKI's accurate calorimeter applicable to Hydrogen and the other various gases.


OHC-800 is applicable to a variety of gases and application including hydrogen by customising OHC-800 in accordance with customers’ operating environment and requirement.

This real-time gas calorimeter is based on our patented detection principle, called OPT-SONIC. By combining an optical sensor and a sound velocity sensor to perform unique calculations.

Technology advantages

  • Continuous measurement (the measuring data is updated per 0.25 sec.)
  • High accuracy (For natural gas, +/-0.4% of indication. OIML R140 class A approval pending.)
  • High-speed response (T90 within 5 sec.)
  • Smooth trackability.
  • Low maintenance cost (No regular replacement parts & sensors. Life time is 10 years.)
  • Low running cost (Minimum measuring gas consumption: 300ml/min)
  • Robustness (Explosion proof FM/ATEX/IECEX, IP67, -20 to 57 degreeC)
  • Various measurement gases (NG+Hydrogen/LPG/flare gas/Off-gas etc.)
  • Unit set-up can be customised to individual customer requirements.
  • Calorific value/Wobbe index/Relative density/Methane number can be output. Compression factor and Maximum Combustion Potential are now preparing to be output.
  • There is NO soot generation which will affect the detection over the time.
  • It is NOT necessary to keep introduce measuring gas into OHC-800


  • Addresses all of gas calorimeter challenges for a variety of gases and applications.
  • Accurate calorimetry of natural gas containing hydrogen such as power-to-gas (H2 injection / methanation / Hydrogen co-firing gas turbine).
  • Controls air-fuel ratios to stabilise combustion process and gas turbine operation.
  • Controls real-time calorific values for stabilising high quality fuel gas trading.
  • Precisely adjusts gas calorific value to minimise fuel consumption and costs.
  • Makes efficient reuse of by-product gas along with environmental considerations.
  • Monitoring flare gas calorie to keep flaming even in low calorie.

Remote demonstration

Remote demonstration can be provided by RIKEN KEIKI. Our R&D Production Plant in Kasukabe, Japan has an OHC-800 demonstration room. Various gases are permanently installed there, and it is possible to mix the gas on the spot according to the customer's request. Customers’ confidence in OHC-800 can be increased by witnessing the quick and accurate measurement of the calorific value of the gas prepared in front of them without any prior preparation.

Remote demonstrations can be conducted using web conferencing tools. Enjoy the fast and accurate measurement!