An apparatus for correcting the weight flow of fluid passing through a fuel control is shown. A bimetallic probe is placed within a metering spool to sense temperature variation of the fuel passing therethrough. A feedback mechanism senses changes in the probe and nulls the spool. The spool cooperates with specially shaped windows in a sleeve so that a percentage change in temperature allows a corresponding percentage change in fuel flow thereby offsetting changes in fuel density (and weight flow) caused by temperature changes. The probe is comprised of a rod and a perforated shell.