GAOHOU PH0-14 Value Detect Sensor Module + PH Electrode Probe BNC For Arduino
- Getting the voltage varies on what you’re using. The PH for this sensor is not at 0v for a PH7 it’s around 2.51v from the multi-meter and PH4 at 3.03. If you calculate the step, 2.51-3.03 =-0.52. The difference between ph4.01 and PH7 is 2.99..
- If you’re using a Particle product like the Photon or Argon, be aware of a bug. It’s a hardware issue with the analog ports fluctuating a ghost voltage. This fluctuation is enough at these low voltages reading to make your ph sway by .7 or more. To fix this, you’ll need to add a 0.1uF cap between the analog port your using and ground..
- This PH electrode probe must be calibrated with standard buffer solution before each use, and the electrode probe cannot be tested continuously for a long time, which will shorten its life. There are two trimmers on the circuit board. One of them is for offset adjustment (closest to BNC connector) accomplished by removing the Ph probe and shorting the BNC connector with a wire. The other trimmer is an upper limit threshold for the digital output pin..