2-Color Pyrometers

2-color pyrometers can measure through polluting lenses, dust or smoke, or when the emissivity of the material is unknown. This is possible by the use of 2 detectors, which measure simultaneously at different spectral ranges and determine the temperature by forming the radiation ratio (the quotient).

In this method, it is not necessary to know the emissivity of the measured material. It is reduced out because the radiation ratio remains constant at a neutral attenuation of infrared radiation (by dust, smoke …).
2-color pyrometers are available as stationary devices in series Metis M3 and H3 as well as handheld portables Capella C3 in various versions.

In contrast, 1-color pyrometers are used wherever there is a clear view without disturbances such as dust or other contamination between the pyrometer and the object to be measured.

Measurements of metals, ceramics, composites, semiconductor, wafers, molten glass…

2-color pyrometers are available in 2 spectral ranges. For metal measurements, the shortest possible spectral range is advantageous for an accurate measurement. There, on the one hand, the emissivities on the two spectral ranges are higher, so that higher signal strengths are captured, which ensure a more accurate quotient calculation. Frequently, also the individual measurement results of the two spectral ranges are more parallel than in longer wavelength ranges, which is necessary to always calculate the quotient correctly at all measured temperatures. However, for technical reasons the shorter spectral ranges start at slightly higher temperature ranges, so that if necessary a model with a somewhat longer-wave spectral range has to be selected.

Spectral range graph with the available spectral ranges of the pyrometers.

We recommend a personal pre-advice consultation before you decide to use a device.

Click on the areas to open the model overview.

Metals (600 – 3300°C)
Series and modelSpectral
range
Temperature
ranges
Response
time
Smallest
spot size
OpticsSighting
methods
Capella C309
Series / Datasheet (pdf)
0.75–1.1 µm600–1400°C
750–1800°C
900–2500°C
< 1 ms0.3 mmFocLa
Vf
Metis M311
Series / Datasheet (pdf)
0.75–1.1 µm600–1400°C
650–1500°C
750–1800°C
900–2500°C
1000–3000°C
1100–3300°C
< 1 ms0.8 mmFoc
MFoc
FFoc
La
Vf
C
Metis H311
Series / Datasheet (pdf)
0.75–1.1 µm600–1100°C
650–1300°C
750–1400°C
900–1800°C
1000–2000°C
1100–2200°C
1300–2500°C
< 80 µs0.5 mmFoc
FFoc
La
Vf
C


Foc: Integrated focusable optics, FFoc: Focusable fiber optics, MFoc: Motorized focus optics,
La: Laser aiming, Vf: View finder C: Camera

Metals (300 – 3300°C)
Series and modelSpectral
range
Temperature
ranges
Response
time
Smallest
spot size
OpticsSighting
methods
Capella C322
Series / Datasheet (pdf)
1.45 – 1.8 µm300–1000°C
350–1300°C
500–1800°C
< 1 ms0.3 mmFokLP
Dbv
Metis M322
Series / Datasheet (pdf)
1.45 – 1.8 µm300–1000°C
350–1300°C
500–1800°C
800–3000°C
1000–3300°C
< 1 ms0.8 mmFoc
MFoc
FFoc
La
Vf
C
Metis H322
Series / Datasheet (pdf)
1.45 – 1.8 µm600–1100°C
650–1300°C
750–1400°C
900–1800°C
1000–2000°C
1100–2200°C
1300–2500°C
< 80 µs0.5 mmFoc
FFoc
La
Vf
C


Foc: Integrated focusable optics, FFoc: Focusable fiber optics, MFoc: Motorized focus optics,
La: Laser aiming, Vf: View finder C: Camera


All devices measure with high precision and with high optical resolutions, so that it is possible to measure even at larger distances to the measuring object still with small spot sizes. Stationary devices are used for continuous monitoring, hand-held devices for comparison measurements with these or for random checks at various points.