Chain Float:

This category of float gauge has a float ranging in size  up  to  12  inches  in  diameter  and  is  used where small level limitations imposed through ball floats  have  be  exceeded. A range of level measured will be limited only through the size of the vessel. The operation of the chain float is same to the ball float except in the method of positioning the pointer and in its linked to the position indication. The float is linked to rotating components through a chain along with a weight attached to the other end to gives a means of keeping the chain taut in during changes in level that was show in below figure.

Figure: Chain Float Gauge