Can D50 be used as another name for average particle size?
It is a median on the stated distribution basis, not a universal average. Compare like definitions and examine the rest of the distribution where coarse or fine fractions matter.
Read the distribution basis and size definition before comparing numbers. A volume-based D50 identifies the point below which half the reported volume lies; it is not necessarily the arithmetic mean or a number-based median. Keep the software output definition with the result, including whether data describe percent smaller or percent larger.
How do two batches with the same D50 differ?
Compare D10 and D90 on the same cumulative basis. Two batches can reach the same midpoint while one contains a wider fine or coarse tail. If the quality specification concerns oversize, inspect the fraction above its threshold directly.
Method details to record
| Consideration | What to record |
|---|---|
| Output definition | Percentile, mean or distribution |
| Weighting basis | Number, volume or intensity |
| Reporting direction | Smaller than or larger than |
Can software-derived surface area replace an adsorption measurement?
Calculated surface depends on the size distribution and geometric assumptions. Gas adsorption probes the surface accessible to the adsorptive under the measurement conditions. State which property the specification uses before comparing values.