Sensors are a key part of any control system and have an impact on the cost, stability, and accuracy of any control system. But they are also something that frankly gets little attention as we design systems, develop specifications, and write sequences. For many designers, the sensor section sits in the back of the product area of the specification and may get little attention or changes from project to project. In general, that is not all bad, but you should go back and periodically review your sensor specifications.