Brewer, W.; Bryan, J.; McClure, E.; Pearson, J.
UCRL-12409; 66p. 22 February 1965.
A Lawrence Radiation Laboratory investigation of thermal effect in dimensional metrology shows that, in the field of close tolerance work, thermal effect is the largest single source of error, large enough to make corrective action necessary if modern measurement systems and machine tools are to attain their potential accuracies. This paper is an effort to create an awareness of the thermal environment problem and to suggest some solutions. A simple, quantitative, semiexperimental method of thermal error evaluation is developed. It is shown, experimentally and theoretically, that the frequency of temperature variation is as important as the absolute limits of the temperature variation. and that the sensitivity of machine structures to thermal vibration can be minimized by selecting environmental frequencies to avoid resonant conditions. A relatively simple device to monitor the thermal environment and automatically effect error compensation is proposed.