High-Temperature Furnaces: Non-Contact Temperature Measurement

KELLER pyrometers measure through small furnace openings to support temperature control in demanding vacuum and inert-gas processes.

Accurate temperature measurement is essential for consistent product quality in high-temperature processes such as graphitisation and sintering. For manufacturers working with graphite, carbon materials and technical ceramics, restricted optical access and demanding furnace conditions make selecting the right measurement system particularly important.

KELLER offers pyrometers that measure hot surfaces without contact through furnace viewing ports. Focusable precision optics allow the measuring spot to be matched to the target, even where access through the furnace insulation is limited.

CellaFurnace PX 46: two-colour measurement up to 3,200 °C

Developed for vacuum, inert-gas and high-temperature furnaces, the CellaFurnace PX 46 covers a continuous measuring range from 900 to 3,200 °C. Its two-colour principle determines temperature from the ratio of radiation measured at two wavelengths.

This method can reduce the influence of partial signal attenuation, including certain types of window contamination, when both wavelength channels are affected similarly and sufficient signal remains available. Focusable optics and optional video sighting support accurate alignment through small furnace openings. An analogue output and IO-Link interface enable integration into process monitoring and control systems.

CellaTemp PA 35 AF 11/C: short-wavelength measurement with video sighting

The CellaTemp PA 35 AF 11/C provides single-colour measurement from 600 to 3,500 °C. Its short-wavelength spectral range, focusable optics and integrated video camera make it an option for applications with suitable target emissivity and optical conditions. Analogue, USB and RS485 interfaces support connection and data acquisition.

A measurement solution matched to the furnace

Reliable results depend on the complete installation: target material, temperature range, viewing distance, opening dimensions and window transmission. The pyrometer measures the surface in its field of view, so the measuring position must be selected to represent the process temperature of interest.

Contact KELLER Pyrometer Systems to discuss your furnace application and select the appropriate pyrometer, optics and mounting accessories.