Grease analysis poses some unique challenges. Sample size is often very small yet contamination levels and particle sizes involved are often anything but! The most challenging bit is getting the sample dilute enough to pass through the fine capillaries of an ICP without clogging them up and damaging the instrument. And that’s before you start looking at the size of the debris? How do we manage? By not using an ICP! We use a Rotating Disk Electrode spectrometer instead. Problem solved.
In an RDE Spectrometer the sample is picked up by a rotating disk electrode dipped into the test pot. Energy is then introduced into the system in the form of an electrical spark. Light emitted by the energised sample is collected and analysed with levels of multiple elements obtained by comparison to a calibration standard.