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.
Concert pitch. Concert pitch refers to the pitch reference to which a group of musical instruments are tuned for a performance. Concert pitch may vary from ensemble to ensemble, and has varied widely over musical history. In the literature this is also called international standard pitch. The most common modern tuning standard uses 440 Hz for A above middle C as a reference note, with other notes being set relative to it.