Manholes / Pipe-Mic (Again)

> I kind of like that Empire one - it says reads within 1 degree which should be plenty good to get the required accuracy.

At shallow angles they're fine, but I've run into plenty of situations in which it gets a little iffy due to large angles. Around here it's not uncommon to have angles of 20° to 25° on inverts coming from curb inlets. With a 6-foot measurement and a nominally 25° angle, an error of 1° is about 0.05 foot. And it's pretty hard to nail those cheap clinometers -- the one I have, which is similar to the one pictured -- down to 1° with any certainty.

Yes, good point. I was thinking of the deep manholes I was doing where the angle wasn't too sharp.