Instrumentation is the art of measuring the value of some plant parameter, pressure, flow, level or temperature to name a few and supplying a signal that is proportional to the measured parameter. The output signals are standard signal and can then be processed by other equipment to provide indication, alarms or automatic control. There are a number of standard signals; however, those most common in a Boiler plant are the 4-20 mA electronic signal and the 20-100 kPa pneumatic signal. This section of the course is going to deal with the instrumentation equipment normal used to measure and provide signals. We will look at the measurement of five parameters: pressure, flow, level, temperature and neutron flux.