1990 - Volume #14, Issue #5, Page #32
Sample Stories From This Issue | List of All Stories In This Issue]

    «Previous    Next»
Laser Beam Cattle Gate
New electronic "gate watch" works by projecting an invisible infrared beam across the gate opening.
A photo-electric sensor mounted on one side of the gate sends out a beam toward a reflector mounted on the other side. When an animal breaks the beam, a high-decibel warning blast goes off along with a flashing str..........


  You must sign in, subscribe or renew to see the page.


   You must sign in, subscribe or renew to see the flip-book



To read the rest of this story, download this issue below or click here to register with your account number.
Order the Issue Containing This Story
1990 - Volume #14, Issue #5