Tuesday, December 22, 2015

Simple Field Verification of Thermal Mass Flow Meter Calibration

Magnetrol brand industrial thermal mass flow transmitter for measuring mass flow of air and gases
Magnetrol TA2 Thermatel
Thermal Mass Flow Transmitter
Courtesy Magnetrol
In processes that require mass flow measurement of gases or air, thermal dispersion measurement technology is often selected for use. Its direct mass flow measurement and other attributes make this technology a favorable alternative for many applications, including combustion air, compressed air, natural gas, aeration air, vent lines, biogas production, vent lines, hydrogen lines, and more.

schematic of dual sensors on thermal mass flow meter
Schematic depiction of dual
temperature sensors on a
thermal mass flow meter
Courtesy Magnetrol
As it name implies, a thermal mass flow meter calculates flow by using temperature measurements. Two temperature sensors are inserted into the flow path. One measures the media temperature, the other is heated by a measured power source. With a device factory calibrated for a specific medium, the amount of heat transferred away from the heated sensor can be known, and will be proportional to the mass flow rate of the medium.

Some of the key attributes of thermal mass flow measurement devices:

  • Comparatively moderate initial cost
  • Compatible with measurement of low density gases that cannot be achieved with some other methods
  • Provides direct mass flow measurement
  • Most devices have option for output of process temperature
  • High turndown, with strong signal at low flow rates
  • Field calibration verification
Verifying the proper operation of transmitters of any type can be challenging, especially if performed in the field. The video below demonstrates how the Magnetrol TA2, a thermal mass flow transmitter, can have a calibration verification performed on site with a simple procedure.

The video is short and concise, with some valuable technical knowledge to build your understanding of how this technology works. More detailed information about mass flow measurement, or the specific devices shown in the video, is available from a product application specialist. Share your process measurement and control challenges with them and collaborate to develop the best solution.