tlvp wrote:

John Harmon wrote:

I am confused

Same here, but about temperatures using wall thermometers: people always
spec out temperature in degrees but all I see is how many inches the column
of mercury is, no idea how to convert degrees into inches here either

Smartphones contain 3-axis accelerometer chips and magnetic compass
chips, but AFAIK (unlike digital levels) they don't contain an
inclinometer chip, so the accuracy from a phone is not likely to be
high, the "bubble level" apps you can get for phones are a bit of a
joke, they'll probably be influenced by large chunks of metal nearby.

The spec of the MEMS inclinometers in digital levels seems to be +/-6
minutes when measuring horizontal or vertical and +/-12 minutes for
other angles, so even they would be marginal.