The PyroMetrixTM Acoustic Pyrometer is a non-contact measurement device that obtains highly accurate instantaneous gas temperature data in any area of the boiler.

The PyroMetrix system utilizes the principle that the velocity of sound through a medium is related to the temperature of the medium. Instantaneous temperature data is spatially averaged and can provide zonal temperature maps.

The PyroMetrix system generates a sound wave with a very sharp rise time and measures the time it takes to traverse the chamber. When the distance between the sound source and the receiver is known, the average temperature between the two points can be determined. The system can distinguish between equipment sounds, such as sootblowers, which are of limited duration, and persistent sounds, such as tube leaks.

PyroMetrix Acoustic Signal Generators (ASGs) can be mounted horizontally or vertically to accommodate space restrictions.

PyroMetrix Acoustic Signal Receivers (ASRs) detect sounds in the boiler via a tube through the wall and are housed in pressure-sealed NEMA 4 enclosures. Boiler tube bends are not required to mount the ASRs.

Key applications for the PyroMetrix Acoustic Pyrometer include furnace exit gas temperature (FEGT) and temperature distribution measurement.

Benefits include the ability to:

  • Significantly reduce slagging by maintaining optimal FEGT temperatures
  • Avoid tube damage and leaks by avoiding hot spots and thermal shock
  • Improve heat transfer rate by balancing combustion
  • Reduce emissions by managing critical temperature profiles

PyroMetrix offers significant technical advantages over traditional technologies:


The PyroMetrix system provides instantaneous, spatially averaged temperatures with less than 1% error. In contrast, thermocouples provide only point measurements and are subject to radiant heat effects, whereas IR pyrometers are spatially and temporally limited and must also compensate for emissivity errors.


The PyroMetrix system is designed for superior reliability in hot, dirty environments. Ports are cleared by periodic air blasts and components are not sensitive to dust or dirt. This contrasts with optical pyrometers, which require optical train maintenance and port cleaning. Routine seal maintenance for the PyroMetrix system is required every 6 to 12 months, and field service is available on a contract or individual visit basis.

Configuration Flexibility:

The PyroMetrix system can be configured to meet your monitoring needs. ASGs or ASRs can be added as desired.

Click here for a PDF datasheet about our PyroMetrix Acoustic Pyrometer and complementary accessories.