In many manufacturing facilities, sumps can be a big problem. Seldom do you know what is going to end up in the sump; it can be anything from acid to tar. In a situation like this, the DELTA M thermal differential level switch is ideal since it has no moving parts to stick and is available in many exotic materials that are compatible with most chemicals. The DELTA M multi-point level switch is ideal for these applications. The switches can have from 2 points to 6 points with 3 or 4 being very common. In power plants, for example, you may want additional points for booster or back-up points.