If the output from one device is not compatible with the input supplied to another device, what must be applied?

In this scenario, when the output from one device is incompatible with the input requirements of another device, a converter must be applied to ensure compatibility. A converter modifies the signal characteristics from one form to another, making it possible for different types of devices to communicate effectively.

For instance, if one device outputs a voltage signal and another device requires a current signal, a converter would be necessary to change the signal type so that the second device can properly interpret and respond to it. This function is crucial in instrumentation and control processes, where different devices often operate on varying signal types and standards.

While transducers, controllers, and filters are important components in instrumentation, they serve different purposes. A transducer typically converts energy from one form to another (like mechanical to electrical), while a controller manages the operation of different devices within a system. Filters are used to remove unwanted frequency components from signals but do not change the basic signal type. Hence, the application of a converter is essential for ensuring that devices with differing signal characteristics can work together seamlessly.