In most industrial processing plants, there are numerous pieces of rotating machinery, i.e. pumps, turbines, various drive shafts, etc. A lot of these have oil seals (or bearing seals).

The larger equipment usually has an oil reservoir to supply either a group or individual seals. The fluid is normally lube oil or transmission fluid. Almost all of these will have a sight glass to show the operating level.

These sight glasses are ideal candidates for replacement with a magnetic level gauge. It gives them the normal advantage of visibility from a distance, the ability to add alarm switches and improved safety.

There are many large, expensive pumps in industrial plants. If one goes down because a bearing or seal fails, it can be a very expensive proposition in terms of both repairs and lost production.