Calibration

Mechanical by Peter Scott

Physical Calibration

A mechanical calibration protocol study is currently under way to examine whether mechanical calibration is equal to or better than calibrator tablets. However opinions vary in regards to eliminating or reducing chemical calibrators.

Calibration parameter	Current USP tolerances	Point of measurement	Proposed tolerances	Proposed frequency
Height check	25+-2mm	Paddle/basket bottom	25+-2mm	At time of use if vessels are removed
Basket wobble	+-1mm as runout	Bottom of basket rim	+-1.0 mm total run out	Every 3 months
Rotational speed	+-4%	Not applicable	+-1 rpm	Every 3 months
Vessel-shaft centering	2mm from center line	Center line	2mm from center line	Every 3 months
Vessel temperature	37+-0.5C	Not applicable	37+-0.5C	At time of use
Bath levelness	Level	Base plate	Level	Every 3 months
Shaft wobble	no significant wobble	2cm above top of paddle blade	<0.5 mm total run out	Every 3 months
Paddle/basket dimensions	See USP	See USP	See USP	Upon receipt
Vessel dimensions	See USP	See USP	See USP	Upon receipt
Degassing technique	NCDA2 passes calibration	Not applicable	NCDA2 passes calibration	Once per year
Proposed parameters under investigation
Paddle/basket examination	None	Not applicable	No gross defects as determined by visual inspection	At time of use
Shaft verticality	None	Above vessel	Vertical as measured by a bubble level	Every 3 months
Visual inspection of belts; check ball bearings	None	Not applicable	Belts are tight, clean, free of cracks, properly aligned; shaft turns freely	Every 3 months
Vibration	None	Base plate while operating at 100 rpm	<0.2mil	Every 3 months

Literature Cited: Pharmacopeial Forum: Volume 26, Number 4