The Design of a Dielectric Spectrograph

The design and principle of operation of a transistorized dielectric spectrograph operating at a frequency of 1650 ±1 MHz are presented. The apparatus has high sensitivity and can measure the dielectric constant to a relative uncertainty of 1×10-7 and the loss tangent to about 2×10-7. It can be used up to pressure ranges of 100 atm or better. The apparatus is particularly useful for the quick measurement of very small dipole moments (less than 1 Debye) to an accuracy better than 1 percent. The results for mixtures of helium with 1) carbonylsulfide, a linear molecule, 2) carbontetrafluoride, a spherical top, and for 3) pure nitric oxide, a diatomic molecule, are briefly presented.