Sweep blend command measure Diameter

I made part using Sweptblend command. Trajectory at both end is straight & all sections are round. As attached image When I measure Diameter at the end it does not shows. Instead of it Arc length showing. Also It cant assemble in assembly by coincident constrain. So I have to made it by Sweep & Swept Blend command with using Three or Four command.

So What is way to do it by Swept-Blend.

Thanks.