Automatic Gate Research Articles

Digital read-out echo sounder

The trend towards automation in hydrographic survey and oceanography calls for automatic read-out of depth from an echo sounder. A system of signal selection is described which includes an automatic time gate synchronized with the sea-bed echo. Automatic gain control is also used to maintain optimum amplitude discrimination throughout varying conditions. A recording echo sounder forms an integral part of the apparatus and is used to check the signal selection by identification of the selected echo

A Simplified Rotary Fish Screen and an Automatic Water Gate

A simplified, rotary fish screen and an automatic water gate have been developed for use in streams or hatchery raceways. This self-cleaning screen is designed to replace stationary, vertical screens which become plugged with leaves, sticks, and other water-borne debris and require periodic cleaning in order to prevent water level fluctuations in raceways. It is of simple construction, operates for long periods, and is readily portable. It is not designed to replace large-capacity, gear-driven rotary screens. The gate is used in conjunction with a gear-driven rotary screen, and is designed to open automatically during floods and pass water through the screen and to close automatically and seal off the screen when the water recedes to a normal level.