what is fg in catheter
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 1â3 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.