The MIT DMSE Breakerspace is a materials exploration lab open to all undergraduates.
HomeThis instrument gives particle size distribution data for dry powder samples with particles between 0.24 and 2,000 microns using laser diffraction.
The sequence of steps to run a measurement is very straightforward: start the software, connect to the instrument, let it initialize, verify you are saving into the correct database, load a measurement SOP, clean the sample tray if needed and load a sample, run the auto-sequence, save your data, and close the software. In the instructions and videos below the steps to prepare the instrument (cleaning, sample loading, sample collection) are show independent of where they occur in the timeline of operating the instrument in software. Please refer to the SOP section, above, for the chronological sequence of the entire operation (instrument initialization, sample loading, collection, finishing).
Loose particles in the sample area from previous samples can be pulled in to the instrument and skew your result. If there are particles to clean, lightly wet a Kimwipe with isopropanol and use it to wipe up loose particles. If needed, the sample tray and sample tray carrier can be removed for more careful cleaning. This video shows the cleaning process:
This video shows a typical sample loading process:
Since the organization of the software can be confusing, this screen capture video shows the full sequence of steps needed to start the softare, initialize the instrument, and collect and export data. Don’t forget, of course, to load your sample after selecting your measurement SOP and before starting the ‘auto-sequence.’
After your sample is loaded and the sample tray door is closed, and you run the auto-sequence (editing title, sample ID, and notes as appropriate), the auto-sequence will begin. The shop vacuum under the instrument will come on and run for several seconds. This is to make sure any loose particles are pulled into the instrument and cleared from the analysis chamber before the setzero is run. Next, the setzero will run. Setzero is the process that the instrument uses to determine the background signal when the instrument is collecting data but no sample is being fed into it. Once the setzero process is completed, the sample tray will begin to move under the sample collection nozzle, and the sample will be pulled in to the instrument. After the sample is pulled through the analysis chamber it is collected in the shop vacuum below the instrument, with two implications: 1. there is little to no cleanup that you will need to do, and 2. there is no way to recover the powder that you analyze.
This video shows the full sample collection process:
Data is automatically saved in the database that is active at the time the auto-sequence is started, so it will not be lost (short of a hardware failure in the workstation) and you can review it and export it at any time. The software also prompts you to automatically save the report that is generated after the sample is collected. The distribution shown in the report can be recalculated to show a distribution based on particle diameter, particle volume, or number of particles of a given size-range. The data produced by this instrument is fairly straightforward, but please ask lab staff if you have questions about data processing and analysis.