Hi – it’s Debbie here again. Although I’ve been quite busy over the last few weeks helping new Morphologi G3 users get started, I just thought I would take a few minutes to pass on a few more hints and tips about how you can get the best out of your Morphologi G3.
Issue: Where do I start when developing a new imaging SOP?
Tip: Employ fixed focus
Fixed Focus for first time measurements and SOP setup
A good tip when first setting up SOPs for the Morphologi G3 is to use fixed focus with the offset set at zero microns. By setting the focus position at the surface of the glass substrate all the small particles will be in focus. The reasoning behind this is simple. If the sample is polydisperse you will not be able to focus simultaneously on both small and large particles.
The large particle error that results from focusing on smaller particles is far less significant than the potential loss of small particles that might result when focusing on a large particle.
If you are measuring a monodisperse sample, you can instead set the focus manually the first time and then fix that focus position for all future measurements.
In addition, fixed focus improves reproducibility of measurements between different Instruments and different users when results need to be compared.
A good example of the application of fixed focus measurements may be found in a comparison of particle size and shape for atomised metal alloys used in injection moulding. Comparison of metal powders produced by different atomization processes for metal injection molding using the Morphologi® G3S is published on the Malvern website and may be accessed via the Malvern Instruments knowledge bank.
I hope you find this advice useful. If you have any questions at all I would be glad to help, so please get in touch.