APPARATUS FOR MEASURING WATER LEVEL

PURPOSE:To accurately measure a water level by preventing that condensed water is stored in detection piping on a steam side and air bubbles are generated in detection piping on a water side even in such a case that a differential pressure type water level measuring apparatus is used under a vacuum condition. CONSTITUTION:The detection piping 2 on a steam side transmitting the pressure in a tank 1 to a differential pressure transmitter 4 is heated by a heater 7 and the condensed water generated in the piping is evaporated to be discharged to the tank 1. Piping 14 opened to the atmosphere at one end thereof is connected to the detection piping 2 on the steam side and a proper amount of air leaking from the piping 14 is discharged to the tank 1 held under vacuum to prevent the inflow of steam into the piping 2 from the tank 1. A differential pressure measuring device 4 is anchored 10m lower than the bottom part of the tank 1.