v.3.x Random Interval Generator ("Beeper")
Russell T. Hurlburt, Ph.D.

This is the beeper used in the Descriptive Experience Sampling studies conducted by Dr. Hurlburt and his colleagues.


The random interval generator v.3.x. creates either random or fixed intervals that are terminated by audible beeps. The beep is a 700hz tone that is delivered through a switchable onboard speaker or an external earphone, both controlled by a volume control. Random-interval or fixed-interval mode is selected by a switch inside the case. The interval lengths are easily programmable by switches inside the case from a mean length of 5 minutes to a mean length of 4 hours. If the device is left unattended, it enters a battery-saving "chirp" mode. Dimensions (inches): 4.15 X .85 X 2.40. Weight including batteries: 4.5 oz. The photos are actual size.

Operating instructions.