A correctly calibrated sensor can still control the wrong condition when it is installed at an unrepresentative location. An oven sensor near a frame may overreact to edge loss, while a mold sensor near a coolant inlet may remain stable as remote cavities overheat.
The sensor location should be compared with thermal maps and the physical heat-flow path. A control signal that remains steady while part behavior drifts suggests that the measured point is not following the critical region. Response delay and mounting depth must also be considered.
Sensor positions should be selected to represent the controlled variable rather than the easiest mounting point. Large tools and ovens may require multiple measurements or a defined mapping procedure. Recipe limits should state the location and cycle point associated with each value.