A: Process gauges provide a means to monitor variables of the thermal environment. Skilled operators become attuned to “normal” gauge readings. If another aspect of the process changes one of the first reacting variables is the process heat load. As such, gauge variations are often early indicators of control loss, and are useful to diagnose issues. Test fittings are a useful means to maintain components and identify abnormalities when gauges are insufficient or other test methods are necessary.