Liq. level monitor using induction in prim. and sec. coils - has tube with coil pairs spaced inside and float outside affecting one field for signal

摘要

A replaceable liquid level meter operates on the inductive principle. It is use for liquids with low electrical conductivity. It consists of a tube which contains a primary and a secondary coil. The primary coil is excited with constant a.c. which induces a voltage in the secondary coil. There is a float (8) which slides up and down around the circumference of the tube (3). There are primary and secondary coils (4, 5) placed at given points along the tube. The float can only influence the field of one of the coil pairs at any one time. This generates a signal to indicate whether the float is below or above that measuring point.