Offset
Offset turns up in 2 fields: electricians, metrology. Here is what it means to the people in each one.
Offset in electricians
Two equal bends in opposite directions that shift a conduit run sideways to clear an obstruction or enter a box.
An offset moves a conduit run onto a parallel line by bending it one way and then back by the same angle. The distance between the two bend marks equals the offset depth times a multiplier: 6 for 10 degrees, 2.6 for 22.5, 2 for 30, 1.4 for 45 and 1.2 for 60. Every offset also shortens the run slightly, the shrink, which is added when the offset is measured toward an obstruction. A small offset into a box is a box offset.
"Six-inch offset with 30s, so mark them twelve inches apart and add an inch and a half for shrink."
Offset in metrology
A constant error that shifts every reading by the same amount, most often seen as a nonzero reading at zero input.
A fixed shift in an instrument's output relative to the correct value, most visible as a nonzero reading with zero applied, such as a DMM showing 3 µV with shorted leads or a balance showing 0.2 g with an empty pan. Zero offsets are usually nulled with a zero or tare function before measuring, and any residual offset is corrected or carried in the budget. An offset adds the same error everywhere, unlike a gain error that grows with the reading.
"Short the leads and null the offset before you take the low-range readings."