An International Comparison of Frequency by Means of a Luminous Quartz Resonator

The international comparison of frequency standards made with the luminous quartz resonator shows the different laboratories,-Physikalisch-technische Reichsanstalt, National Physical Laboratory, Bureau of Standards, and Electrotechnical Laboratory,-to be in agreement to one part in 10
⁵
when used to calibrate the resonator at its flexuralfundamental of about 10 kc, due allowance being madefor the temperature coefficient of the resonator in this mode, namely, about 1 part in 10
⁵
and negative. The observed agreement seems limited by the luminous glow resonator used rather than by any difference between the laboratory standards compared.