Which device actively measures water flow through a piping system and reports its data to the computerized central control system?

• A. Temperature Sensor
• B. Flow Sensor
• C. Humidity Sensor
• D. Pressure Sensor

Answer: (B)

Measuring how much water is moving through a pipe in real time requires a device that directly senses the flow rate and can send that information to the central controller. That device is a flow sensor (flow meter). It is designed to quantify the rate or total volume of water passing through the system and typically outputs a signal—analog or digital—that the centralized control system can read, log, and use for automatic controls, alarms, and reporting.

Different types exist, such as turbine/paddle-wheel, magnetic, ultrasonic, or differential-pressure meters, but the common function is to actively determine flow and relay the data to the control system. By contrast, a temperature sensor only measures water temperature, a humidity sensor monitors environmental moisture, and a pressure sensor measures pressure without directly reporting the actual flow rate, so they don’t fulfill the same role in conveying flow information to the control system.