Larger diameter diaphragms have lower spring rates compared to smaller diameter diaphragms. Consequently, they are more flexible. As fill fluids contract and expand with temperature gradients from the process and ambient conditions, the larger diameter diaphragm can deflect without conveying a pressure change to the sensor. The smaller diameter, rigid diaphragm will not deflect as much and will cause drift in the pressure sensor reading proportional to the temperature change. This drift is usually small in magnitude.