I recently bought an Atlas Scientific EC probe (literally the day before the anyleaf EC probe came out for 1/6th the price!), naturally it needs temperature compensation. I know my Anyleaf pH probe has an integrated temp sensor that it uses for temperature compensation. I had a look through the Anyleaf python library and it seems that pulling temperature data alone is easy enough.
I was thinking it would be easier to get the pH probe to return it’s temperature data in the same way a DHT11/22 returns multiple measurements (temp, humidity, dewpoint, etc - as one input with multiple measurements.
Any problems with this approach? Is there a good reason to buy a dedicated temp probe instead?
According to the EC datasheet (as well as for pH), the temperature sensor is on the board, not the probe:
The onboard temperature compensation sensor (Texas Instrument LM61) is only suitable for uses in situations where the temperature of the solution being measured is at a similar temperature to the ambient air temperature the module sits in. This is a reasonable approximation in some cases, but is unsuitable for measuring solutions that differ in temperature, such as large bodies of water, or heated/cooled solutions. It’s also unsuitable if the module is placed in an enclosure that is warmer or cooler than the surrounding air. In these situations, or for the most accurate temperature compensation, it’s recommended that you use an external temperature sensor immersed in the substance being measured.
So if you want to measure the air temperature, it could be a nice addition to the Anyleaf EC module (to record the air temperature measurement to the Mycodo database). If your air temperature differs from your water temperature, you may want to consider using a dedicated temperature sensor you can submerge in your liquid.