How To Test Metalworking Fluid Health Using pH, Conductivity, and Microbial Counts
Most coolant sumps give plenty of warning before they fail. The pH slides a few tenths over three weeks, conductivity creeps upward after every top-off, and a dip slide that used to come back clean starts showing colonies. By the time anyone notices a rotten-egg smell on Monday morning or rust spotting on finished parts, the fluid has usually been in trouble for a while, and the cheapest window to fix it has already closed.
