LICOR 6251
(this photo of the model 6252)
ISFS has one Li-Cor 6251, purchased many years ago primary for laboratory testing of other carbon dioxide sensors. The CO2-only model was chosen since its signal-to-noise ratio is a factor of 2 better than the CO2/H2O model 6252. Our model had analog output. This sensor is no longer used.
6252 Specifications (with H2O, thus worse for CO2)
Websites
Typical Sampling Rates
10Hz