Industry Perspective on Pressure Drop Measurement (NM)

NM provided an update at work conducted at Vectura to support Darryl’s investigations, and provided an industry perspective on using ΔP measurements for in-use impactor monitoring.

Vectura are currently gathering data on their in-use NGI’s to determine whether the ΔP measurements are sensitive enough to detect atypical impactor results. They are currently awaiting mensuration of the uncleaned NGI to determine correlation of ΔP with changes in nozzle diameter.

The presentation raised the following observations:

• JTS asked if analytical noise could mask ΔP effects? (team concluded that more data is needed to assess this)
• CB raised the issue of whether the MOC performance could be assessed in any way
• JM/DR commented that if shown to be useful this could form the basis of a future system suitability test

MC/DR commented that the issue of whether impactor manufacturing tolerance limits were appropriate for in-use limits. If these could be widened would ΔP be more useful?