Spectral properties in the near-infrared range A5-IN and A250
A250
-The spectral sensitivity of the A250 pyrometer is the spectral properties superposition for two components:
-Spectral sensitivity of InGaAs -1.7mkm photodetector and cutting filter 1400nm.
-The short wavelength limit created by the multiplication of two curves, and its 5% cut-off is near 1.38-1.4mkm.
-The photodetector long wavelength limit determines extended wavelength limit is 1.7mkm, But the effective wavelength of the superposition is about 1.6mkm ±30nm. This value is mentioned in the pyrometer specification.
Sample of spectral response
The spectral sensitivity after the above superposition of the A250 pyrometer
Optical scheme of dual wavelength pyrometer A5-IN
Pyrometer A5-IN filters specification
BBP-1080-1430nm
CWL=1300nm±30nm
Cut on 5%: 1080±50nm
Cut off 5%: 1430±50nm
Blocking 300-1000 and 1600-2000nm with OD≥3
HWL ≥ 300nm (filter width on 50% of maximal transmission)
BP 1600-90 nm
CWL =1600nm ± 20nm
Cut on 5%: 1910±75nm
Cut off 5%: 2350±75nm,
HWL ≥90-100nm (filter width on 50% of maximal transmission)
Average transmittance: >70%
Blocking 300-1830 with OD ≥3