The Model 6308 shown here was manufactured by 'Keeler Polygraph' which was a division of 'Associated Research' of Chicago, Illinois. This instrument was used in the late 1960's, initially in the Military, and continued being used until the late 1970's in some States. The Model 6308 is one of the first instruments that can easily be changed from a desk mount to a portable unit without tools. The instruments three separate channels provide continuous recording of changes in heart rate and blood pressure, breathing rate and skin resistance. The G.S.R. component consisted of a pair of finger electrodes, or a hand electrode connected to a input circuit of a direct couple solid-state amplifier with a balanced differential output, feeding the pens.

The 6308 utilized a newly designed epoxy encapsulated printed circuits that assured long, trouble-free operation, and like the Model 6318, operated on four nickel cadmium batteries which were automatically recharged when the instrument was plugged into AC current. The Model 6308 is 18" x 9" x 6" and weighs approximately twenty pounds with its accessories.

The Model 6308 was sold for $1325.00, which included all required detachable accessories and initial operating supplies consisting of chart paper, ink and conducting jelly.

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