A strain gauge normally consists of two strain elements mounted at right angles to each other and in close proximity, so that they are both at the same temperature.
See Fig. 12.11a. The gauge is mounted on the diaphragm with one gauge in line with the direction of maximum strain for strain measurement and the other perpendicular to the line of strain, so that it will not sense the strain,
and is used to provide temperature compensation and signal conditioning for the strain gauge element when used in a bridge circuit.