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1952 Press Photo Supersonic Ray Detectives - mja07198

$12.33
AdID: 3091193

Availability: In stock

Part Number: mja07198

Height: 10.25

Width: 7.75

Details

This is an original press photo. The science of electronics is working on the side of the forces of law and order with new developments being tried out constantly. Research laboratories of Central Watch Service, a Chicago firm that has provided watchmen for Chicago clients for 50 years, are now working on a supersonic alrm system that should prove an effective watchman. The device is a high frequency radio speaker which puts pot sounds that are not distinguishable to the human ear. Bombarding a room with supersonic rays, the speaker forms a pattern of sound which will be broken by any movement. This then sets off an alarm. The steady, unbroken line registers on a scope until some movement breaks the path of the sound waves. Then the scope shows a wavy line. This disturbance relays an alarm to a central station. Adjustments can be made so that a fire will set off an alarm. Photo measures 7.75 x 10.25inches. Photo is dated 12-3-1952.