EN ISO 10555-4 demands the following dimensions for the designation of the nominal size of a balloon dilatation catheter:

	a)	the diameter of the inflated balloon, or for multi-diameter balloons the diameter of each portion,
	b)	the effective length of the balloon,
	c)	the effective length of the catheter,
	d)	the diameter of the largest guide wire, which can be used with the catheter

For the points a) and b) the laser scanning system of the Testing Laboratory is used, which is also used in the examination of the structural behavior. For the recording of the profile curve, the distal range of the balloon catheter is driven gradually through the laser measuring field in the measuring chamber, which is kept at 37 °C. The profile measurement takes place with nominal pressure of the balloon catheter, or, if desired, at pre-defined pressure steps.