This tool is used to measure the wear on the pitot tubes to see wether they are still within limits.

As u see, this gage 1 measures the sides of the point of the probe for damage.

This one passes the test.

Next up is gage 2. This gage checks that the tip is completely round. Gage 2A puts a straight metal surface on the tip of the tube, this gage 2A is then rotated around the probe and at no point is the gage 2B allowed to be able to push between the probe and gage 2A.

Once again, this tube passes the test.

Then the last gage checks the inner and outer diameter of the pitot tube tip.

The tube passes the gage 3A test.

And also the gage 3B test.

On fitting the tube it should be noted that we use steel screws and not titanium ones as are sometimes installed, this is due to the electrical bonding of the pitot tube.

Also the pitot tube's base must be smooth with the surface of the aircraft, check the maintenance manual for the limits.
The probe on the next picture is not the proper way a pitot probe should be installed, it's way too deep in the skin, this one should have been shimmed so that the probe moved outward to get the base of the probe flush with the aircraft skin.

Here's a picture of a shim that could have been used to bring this probe more outwards.

This is a probe that has been shimmed flush with the fuselage.

To further the aerodynamic smoothness of the tube we seal the edges around the probe with aerodynamic sealant.

If the tube has been removed, the system would have to be leak checked again with the pitot static testset.