What instrument measures the pressure inside a boiler?

The instrument that measures the pressure inside a boiler is the pressure gauge. This device is specifically designed to provide a readout of the internal pressure levels within the boiler system, which is critical for safe and efficient operation. Maintaining appropriate pressure is essential, as it impacts the performance of the boiler and ensures that it operates within safe limits.

Understanding the significance of the pressure gauge in boiler operation is key; it allows operators to monitor for any discrepancies that could indicate potential issues, helping to prevent unsafe conditions. Other instruments listed do not perform this function. For instance, a flow meter measures the flow rate of a liquid or gas, a thermometer measures temperature, and a level indicator shows the level of liquid within the boiler, but none of these tools are designed to measure pressure.