Which sensor produces an electrical signal related to temperature?

• A. Temperature Sensor
• B. Wind Sensor
• C. Pressure Sensor
• D. Rain Sensor

Answer: (A)

The main idea here is that a temperature sensor directly converts a temperature reading into an electrical signal that varies with temperature. That’s exactly what a temperature sensor does: it detects ambient temperature and then outputs a signal—often a voltage or resistance—that changes as the temperature changes. Common implementations include thermistors (resistance changes with temperature), RTDs (resistance increases with temperature), and thermocouples (a small voltage generated from a temperature difference).

In irrigation practice, this helps controllers log air or soil temperature to inform scheduling and evapotranspiration calculations. Other sensors measure different things: a wind sensor tracks wind speed, a pressure sensor measures pressure, and a rain sensor detects moisture or rainfall. Their outputs are tied to those quantities, not directly to temperature, so they don’t provide a temperature-correlated electrical signal in the same way.