Where the accuracy offered by Coriolis meters is not required, thermal mass flow meters will usually prove to be a suitable solution.
The thermal mass meter measures gas flow based upon the concept of convective heat transfer. Two sensors are heated within the device to a precise temperature. The second sensor is cooled as the flowing gas passes by so has to be heated to match the temperature of the first (reference) sensor. The gas mass flow can be calculated by measuring the energy required to balance the temperature of the two sensors.
The majority of applications involving thermal mass flow meters are usually for compressed air monitoring from compressors or for leak detection. However, other gases such as argon, CO2, Nitrogen, Hydrogen, Helium, Propane, Methane, Oxygen end even Biogas can all be economically metered.
Flowquip Thermal, or Calorimetric, flow meters are available from ¼” to 2” bore fitted into a stainless steel measuring section (spool piece) with threaded or flanged process connections. The flow sensor is calibrated whilst installed in the measuring section to ensure optimum accuracy and performance. An integral display shows flow rate and total in various volumetric or mass engineering units and also provides a scaled pulse and 4-20mA output. For pipe installations greater than 2” a hot-tap insertion version is available with flanged spool piece options. This flow meter provides a very wide operating flow range with a measuring error of 1.5 to 2%. A special precision calibration is available to provide a measuring error of < 1%. Flowquip can also offer this flow meter with full ATEX Approval. The calorimetric flow meter offers excellent accuracy and reliability at a very affordable price and on a short lead time too.