What are the steps involved in calibrating a temperature sensor in a BAS, and what tools are required?

Calibrating a temperature sensor in a Building Automation System (BAS) ensures that the sensor provides accurate temperature readings. The steps involved in calibrating a temperature sensor include gathering the necessary tools, which typically include a calibrated reference thermometer, a multimeter, and the BAS software or interface. A calibrated reference thermometer serves as the standard against which the sensor is calibrated. The multimeter is used to measure the sensor's output signal, and the BAS software or interface is used to access the sensor's calibration settings. The first step is to verify the sensor's wiring and power supply. Ensure that the sensor is properly wired to the controller and that it is receiving the correct voltage. Next, place the sensor and the reference thermometer in close proximity to each other in a stable environment, such as a room with a constant temperature. Allow sufficient time for both the sensor and the reference thermometer to stabilize at the same temperature. Compare the sensor's reading to the reference thermometer's reading. If there is a significant difference between the two readings, the sensor needs to be calibrated. Use the BAS software or interface to access the sensor's calibration settings. These settings typically include an offset adjustment and a span adjustment. The offset adjustment is used to correct for a constant error across the entire temperature range. The span adjustment is used to correct for errors that vary with temperature. Adjust the offset and span settings until the sensor's reading matches the reference thermometer's reading. After making the adjustments, verify the calibration by comparing the sensor's reading to the reference thermometer's reading at multiple temperatures across the sensor's range. If the sensor's reading is accurate at all temperatures, the calibration is complete. If not, repeat the calibration process until the sensor's reading is accurate across the entire temperature range.