The spectrometer operates with a very intense plasma arc which burns the sample at approximately 13 000 deg C. The light emissions from each element are then measured in intensity and their concentrations calculated in parts per million (PPM) of the element monitored.Tweet
The Spectro analysis results give us an indication of the elemental composition of the wear metals present in a sample. However the Spectrometer is limited, due to its ability to read only particles smaller than 5um; Hence it is not a good failure forecasting tool because of its inability to accurately measure true element levels represented by the larger particles.
In the early stages of failure, larger particles will be generated which pass through undetected by the spectrometer. These particles will not be read until they have been in the system for long enough to be ground into fine particles bypassing through the bearings, gears and other components of the system, often destroying perfectly good equipment as they operate. Hence an entire system is now damaged in all component areas by the time the spectrometer picks it up.
Coupled with the microscopic analysis, which looks at all particle size and shapes, but cannot identify elements, and with the spectrometer identifying the elements but ignorant of size, we are able to monitor wear trends and forecast potential failures early with a very high degree of accuracy. Providing regular samples are taken from the trend, we can identify a potential failure before it becomes a major catastrophe causing severe damage and unplanned shutdowns.
In cases when it may be necessary to identify the predominant wear elements in large particles, we are able to digest the particles in a strong acid solution. This method is called Acid Digestion and is the method by which the spectro analysis results become very accurate. However, it is not a preferred practice due to the slow preparation time and consequently high labour cost per sample resulting in higher sample charges.
Acid digestion is however, a very effective means of measuring and monitoring wear levels in grease samples. The entire contents of the grease sample are digested into solution and all elements fully measured.
The spectrometer also allows us to accurately monitor contamination levels such as dust through Silicon and coolant through Sodium or in marine applications saltwater ingression.
We also look at oil additive levels with the spectrometer, which allows us to trend additive levels, or if the compartment has been topped up with the wrong oil as different types of oil have different element levels in their additives.
Remember regular scheduled sampling allows early failure detection and facilitates shutdown planning which equates to continued production which equal profits.