SEN0161-v2 inconsistent voltage readings
Account cancelled 2020-06-22 13:24:27 3084 Views1 Replies However, in my target solution (pH 6-6.5, verified with a different pH meter), I'm getting voltages of around 1.8-1.9V, putting the measured pH around 5, way off.
The pH probe is then in a container with periodically rising and falling water level, so at times only the tip is submerged and at times the whole length of the probe. Could this be the problem? Is it intended that only the tip of the probe should be submerged and the full submersion causes wrong readings? Of course the BNC connector and signal conversion board are kept dry at all times.
SEN0161-v2 inconsistent voltage readings usually occur due to unstable power supply, wiring issues, or incorrect signal conditioning. The SEN0161-v2 sensor outputs a low-level analog signal, so it is very sensitive to electrical noise and grounding problems. If the sensor and the microcontroller do not share a proper common ground, the ADC may show random or drifting values.
Another common reason is powering the module from an unregulated or noisy 5 V source, especially when motors, relays, or displays are connected to the same supply. Voltage ripple can directly affect the sensor output and cause fluctuation in readings.
Long jumper wires and loose breadboard connections can also introduce interference. To improve stability, keep the signal wire short, use a clean and stable power source, and add a small decoupling capacitor (for example 0.1 µF) near the sensor’s power pins.
Finally, make sure the ADC reference voltage of your controller matches the sensor output range and apply basic software averaging to smooth short-term noise.
Unikeyic Electronics.Pte. Ltd. 
