In a Wheatstone bridge used for temperature sensing, what should the potentiometer R2 be set to balance the bridge at 60°C?

In a Wheatstone bridge setup for temperature sensing, the balance of the bridge is crucial for accurate measurements. The bridge is balanced when the ratio of the resistances is equal, which typically corresponds to specific temperature readings when using temperature-dependent resistors like thermistors or RTDs.

In this case, to balance the bridge at 60°C, the potentiometer R2 must be adjusted to a value that creates a proper ratio that includes the resistance change caused by the temperature variation. Different temperature readings correspond to different resistance values in the sensing element.

The correct choice of 4.4 kohms for R2 at 60°C suggests that it matches the calculated balance condition, taking into account the characteristics of the temperature sensor used in this Wheatstone bridge configuration. The balancing point signifies that the output voltage across the bridge is zero, signifying a perfect balance and accurate temperature reading at that specific temperature.

Thus, understanding the resistance behavior of the sensing element at various temperatures, and knowing that at 60°C a potentiometer setting of 4.4 kohms allows for balanced conditions, illustrates how the proper selection of resistance values is essential in such measurement systems.