A DIGITAL RECORDING DOUBLE FABRY-PEROT SPECTROMETER

J. KUHL, A. STEUDEL, H. WALTHER
1967 Le Journal de Physique Colloques  
A simple and reliable recording double Fabry-Perot spectrometer is described. The linear increase in the first etalon was achieved as usual by means of a pressure reservoir of 200 atm. and a small glass capillary tube. With a second pressure reservoir and a needle valve, the flow rate of which could be changed by a servomotor, the pressure in the second Fabry-Perot was increased. The difference in pressure between the two systems was measured by a mercury manometer, into the limbs of which two
more » ... limbs of which two 15 y platinum wires are immersed. The deviation of the pressure difference changes the lengths of the wires not submerged in the mercury, which means a change of resistance. This variation was detected in a bridge and the amplified signal was used to drive the servomotor of the needle valve thereby increasing or lowering its flow rate. In this way the pressure difference could be kept constant to less than f-0.03 mm Hg. RBsumB. -On dkcrit un spectrometre enregistreur double Ctalon Fabry-Perot d'un fonction-
doi:10.1051/jphyscol:1967258 fatcat:pxnhk6pn5fg4fo62e4ykqwjdiq