1. The measurement range is reduced due to the decrease of the power supply voltage. Replace the battery or correct the power supply voltage.

2. The bias voltage caused by the difference between the ambient temperature and the room temperature exceeds the specified range, and a sensor with a stable bias voltage can be used.

3. Due to the non-linearity of the sensor, a sensor with a large range can be used

4. In the long-distance signal transmission, the constant current of the constant current source voltage is not large enough, the correct voltage and constant current source current can be selected according to the signal frequency amplitude