How to determine the surface temperature and pressure have bad

Temperature and pressure of a surface is designed specifically for hot water heating system, hot water boiler, swimming pool and other equipment design, be able to give a fast and accurate temperature indicator. High water meter can measure pressure PSI and KPA, and water temperature degrees Celsius and Fahrenheit. That how to determine the surface temperature and pressure have bad? Instrument to several common situation for you about the below, if the following cases, the temperature and pressure of a surface is damaged, can't normal use. One, temperature rise or lower temperature and pressure surface pointer does not move; Second, the normal temperature environment, temperature and pressure pointer does not refer to a body surface in normal temperature; Three, temperature rise or reduce the jitter of temperature and pressure when a surface pointer; Four is not allowed, the precision of temperature or pressure precision is inaccurate; Five, pressure pointer is not zero;