An electronic apparatus for testing fatigue by the visual flicker method.

Abstract

A gas-triode controls the flash rate and duration of a neon flicker lamp. Frequency is standardized with a small oscilloscope tube. The apparatus is noiseless, and gives a rapid detn. of the critical fusion frequency since the rate changes instantly. Preliminary expts. show high reliability (r=.99); [sigma]m for 10 tests is 0.1 cycle. The test-retest correlation with a 24 hr. interval is r=.91; the intercorrelation between r. and 1. eye is .95.