On the New Method for Measuring Water Level and Small Pressure Difference

Some of the elementary principles of water level and pressure difference measurement devices are discussed, and these devices were practically made according to the principle. One of these devices is float-type water level meter equipped with swing-arm mechanism which indicate the water surface elevation after magnification. On the other hand, two types of difference meter were made for determining very small difference in pressure precisely. These devices are both very simple in principle and in construction. 1. an inverted bell type difference meter 2. an balance type difference meter by means of these simple devices, the pressure difference was measured very accurately in a different way than ever before, taking note of the weight difference of fluid in manometers rather than the head. These devices, in combination with pitot tube and pitot-static tube, made able to measure local variations of velocity and pressure in the thin flow on the rough wall.