Traffic police speed enforcement device called Archer. These are three hollow pneumatic tubes filled with air exactley one meter apart. As the vehicle crosses the first one it starts a stop watch by means of a micro switch. As it crosses the second, it stops the first stop watch and starts a second. Passing the third tube stops the second stop watch. From the calculation between the two watches, a speed can be determined. ..© SHOUT. THIS PICTURE MUST ONLY BE USED TO ILLUSTRATE THE...
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Traffic police speed enforcement device called Archer. These are three hollow pneumatic tubes filled with air exactley one meter apart. As the vehicle crosses the first one it starts a stop watch by means of a micro switch. As it crosses the second, it stops the first stop watch and starts a second. Passing the third tube stops the second stop watch. From the calculation between the two watches, a speed can be determined. ..© SHOUT. THIS PICTURE MUST ONLY BE USED TO ILLUSTRATE THE EMERGENCY SERVICES IN A POSITIVE MANNER. CONTACT JOHN CALLAN. Exact date unknown.john@shoutpictures.com.www.shoutpictures.com..
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