Format distinction
Aqueous suspension and dry microspheres solve different delivery problems
| Format | Advantages | Risks / controls |
|---|---|---|
| Aqueous PSL suspension | Controlled wet handling, dilution, liquid-counter use, aerosol feed | Background contamination, adsorption, dilution error, surfactant, storage |
| Dry microspheres | Direct dry blending or dry-delivery possibilities | Static, dust, agglomeration, mass-based preparation, inhalation and handling controls |
| Deposited wafer artifact | Ready-to-scan surface reference | Surface contamination, handling damage, tool compatibility and recertification |
Do not create a dry standard by accident
Evaporating an aqueous bottle is not a validated conversion
Drying can leave surfactant or nonvolatile residue, create agglomerates and alter the delivered size distribution. A dry-particle need should be specified as such and matched to a product or validated preparation method.
Hard stop: do not evaporate an aqueous calibration standard and assume the remaining particles retain the certified delivered population.
Selection questions
Define the downstream process
- Will the material be diluted, aerosolized, blended, deposited or sampled directly?
- Is water acceptable in the process?
- What contamination and residue limits apply?
- How will concentration be assigned in the chosen format?
- What safety controls apply to dry powders or aerosols?
- What certificate data must remain valid after preparation?
Applied Physics review
Specify the format in the requirement brief
Use the technical recommendation form to identify wet, dry, aerosol or wafer-delivered requirements. Applied Physics can then route the inquiry to the correct product family or identify a custom-method need.
Applied Physics technical pathway
Match the standard to the measurement—not the other way around.
Send the instrument, medium, target size, concentration, certificate and packaging requirements to Applied Physics for a technical recommendation.