How is cutting oil quality assessed and maintained?

Assessment:

Visual Inspection: Checks for discoloration, cloudiness, or separation.
Chemical Analysis: Measures pH, concentration, and additive levels.
Microbial Testing: Detects bacterial and fungal contamination.
Particle Counting: Determines the level of solid contaminants.
Viscosity Testing: Ensures the oil maintains proper flow characteristics.
Maintenance:

Regular Filtration: Keeps the oil clean by removing contaminants.
Additive Replenishment: Restores depleted additives to maintain performance.
Concentration Adjustments: For water-based fluids, dilutions are corrected as needed.
System Cleaning: Periodically cleans the entire system to prevent buildup.
Microbial Control: Uses biocides and monitors pH to inhibit growth.