I think the guy was actually referring to something a bit different, that is having a second number scale on the caliper that is offset by the width of the first jaw, so you can use the outside jaws for measuring inside dimensions. I don’t think that would work, however.
I was indeed (and I think you’re right, the calipers would need at least to be parallel on their outer edges to work this way).
I’m not sure what rz2000 was doing by (slightly wrongly) rewording basically what I wrote — I get the impression they think I was being full of myself for thinking of a (similar) concept that already exists (despite conceding that it already might) and felt the need to put me back in place.
By using the same scale for inside and outside, you can take one measurement inside, and compare it to something else as outside without moving the scale at all.
I think the guy was actually referring to something a bit different, that is having a second number scale on the caliper that is offset by the width of the first jaw, so you can use the outside jaws for measuring inside dimensions. I don’t think that would work, however.
I was indeed (and I think you’re right, the calipers would need at least to be parallel on their outer edges to work this way).
I’m not sure what rz2000 was doing by (slightly wrongly) rewording basically what I wrote — I get the impression they think I was being full of myself for thinking of a (similar) concept that already exists (despite conceding that it already might) and felt the need to put me back in place.
By using the same scale for inside and outside, you can take one measurement inside, and compare it to something else as outside without moving the scale at all.