Primary gas thermometry by means of laser-absorption spectroscopy: determination of the Boltzmann constant.
We report on a new optical implementation of primary gas thermometry based on laser-absorption spectrometry in the near infrared. The method consists in retrieving the Doppler broadening from highly accurate observations of the line shape of the R(12) nu1+2nu2(0)+nu3 transition in CO2 gas at thermodynamic equilibrium. Doppler width measurements as a function of gas temperature, ranging between the triple point of water and the gallium melting point, allowed for a spectroscopic determination of the Boltzmann constant with a relative accuracy of approximately 1.6 x 10(-4).
Casa
G
G
Dipartimento di Scienze Ambientali, Seconda Università di Napoli, Via Vivaldi 43, I-81100 Caserta, Italy.
Castrillo
A
A
Galzerano
G
G
Wehr
R
R
Merlone
A
A
Di Serafino
D
D
Laporta
P
P
Gianfrani
L
L