The French scale or French gauge system is commonly used to measure the size of a catheter. It is most often abbreviated as Fr, but can often be seen abbreviated as Fg, Ga, FR or F. It may also be abbreviated as CH or Ch (for Charriere, charriÃ¨re its). Inventor The french = size 3 times the diameter in. millimeters round catheter of 1 French has an external diameter of 1â3 mm, and therefore the diameter of a round catheter in millimetres can be determined by dividing the French size by 3: D (mm) = Fr / 3. or. Fr = D (mm) * 3. For example, if the French size is 9, the diameter is 3 mm.
The violin has the highest pitch range of all the string instruments. 5 people found this useful.
Finding Your Highest Notes. 1  1. Find the highest note you can sing in your normal (modal) voice. You want to do the same thing you did for low notes but for the high end of the scale. 2  2. Sing the highest note you can in falsetto.