The Research On The Verification Equipment Of Tide Gauge

Aiming at the wild used tide gauge, a research project has been made. Thepurpose of the project is to built a standard test equipment which is used forcalibration. The principle of the tide gauge is imitating water-level fluctuation ofdiurnal tides or semi-diurnal tides, based on controlling dynamic water flow which is8.5 meters high and 8 tons heavy. The equipment consists of lifter system (it include along guide rail, slider and servo motor etc), CCD level automatic trackingmeasurement system, the bilging and draining system and computer control system.The digital PID control method is used for computerizing the servo motor which drives theslider through a toothed belt on the linear rail for the purpose of CCD camera trace thechanges of water levels correctly. A CCD holder is installed on the slider for fixing theCCD camera. The total length of rail is about 8.8m, three sections butt-jointed. Theprecision linear rail is fixed on a square-shaped pillar. The length of the pillar is about9m which is butt-jointed three sections too. The bottom of pillar is fixed to groundthrough a flange. The top is fixed by a top cap. Processing CCD camera image, opencontrolling valves of the bilging and draining system and the servo motor speedcontrolled is accomplished by the computer control system.The precision linear rail's straightness accuracy is 1mm/9000mm and itstechnical requirement is 2mm/9000mm. This precision is very high and in a leadinglevel domestically. In addition, an over-pressure protected unit consisting of pressuregauges and magnetic valves is involved in the bilging and draining system to preventburning accidents of the pumps when the pressure is over-high.