How many microinches are there in 1 arc second
More information is needed. There isn't a direction conversion for this, because you're comparing apples and oranges. However if you have a bubble level and it says something like . 0001/10 " then conversion can be done using trigonometry and the sine function. . . .
sin(x)= a/b
x=angle in degrees
a = height of inclination of the level, opposite side to angle being measured
b = length of hypotenuse
I believe you're looking for "a. "
If you have a 10 inch level, b = 10, it is your hypotenuse.