As a non-charge service to our customers, Leander & Company will run routine analysis of in-use coolant samples. These analyses include checks of concentration, pH, biological activity and contaminant levels, and so forth. Upon completion of analysis, full reports with any recommended actions are sent to the customer. A full description and explanation of coolant analyses follows.
EXPLANATION OF COOLANT ANALYSIS:
BRIX: This is simply the refractometer reading (Brix scale) using an optical refractometer. The value obtained can be converted to % concentration using a Brix chart.
pH: A measure of the acidity or alkalinity of a system. Most fresh dilutions of metalworking fluid will run between 9.0 and 9.5 pH. This will normally decrease over time. The decrease may be accelerated by contaminants or excessive bacterial growth. A reading of 7.5 or below indicates a seriously degraded system, requiring replacement.
CONCENTRATION: A measure of percent of coolant in the submitted sample based on titration, refractive index or other analytical method.
% TRAMP OIL: Tramp oil refers to any way lube, hydraulic oil or other process oil, not part of the initial coolant formulation which makes its way into the coolant system. Floating tramp oils can seal the surface of a sump, excluding oxygen and accelerating the growth of damaging anaerobic bacteria.
% DIRT: Refers to any insolubles in the submitted sample, determined by filtration through a 15 micron glass fiber filter. These insolubles can include metal fines and/or grinding swarf, as well as other materials. A buildup of these materials can result in abrasive particles being recirculated back through the cutting zone, causing poor finishes to workpiece. Additionally, if these solids settle to the bottom of the sump they can create dead spaces ideal for the growth of bacteria.
BACTERIA: Refers to the level of bacterial activity in the submitted sample, determined by dipslide and expressed in colonies per milliliter. A level of 105colonies/ml is considered the upper acceptable limit for the non-biostable products.
FUNGUS: Refers to the level of fungal activity in the coolant. This level is expressed as negative, slight, moderate or heavy. A fungal presence is not generally considered acceptable, as fungus (dead or alive) can plug screens, filters, lines and/or pumps if not addressed in a timely manner. Unlike bacteria, which disintegrate as they die, a fungal mass will remain intact and must be physically removed from the system.
CONDUCTIVITY: This is a measure of how well a particular coolant sample conducts electricity, expressed in micro mhos (umho). This indicates (roughly) the potential for electrical activity such as corrosion and rusting, although it is also a function of coolant concentration, i.e.: high concentration will cause a corresponding increase in conductivity, but a high conductivity without a high concentration of coolant indicates a high potential for corrosion due to metal ion buildup.
WATER HARDNESS: A measure of the level of hardness minerals dissolved in the water phase of the submitted sample, expressed as parts per million, (ppm) of CaCO 3 (calcium carbonate). Most fluid sumps act as stills, evaporating pure water while leaving hardness minerals behind. As the water is replaced (by more mineral containing water) the level of minerals increases, which can result in sticky, hard or crystalline residue on the machine surfaces.