Hello, everyone! I have been using Arduino for a few years now. However, my skills in it are not as good as others who have studied it. Nevertheless, I am a student from STEM and pursuing Electronics Engineering.
Our research project includes measuring a soil pH, afterwhich we will be storing the value of the pH of soil in a variable. Then, we will use this value to compare to a neutral soil pH which is 7.
If the soil is alkaline, then we will need to lessen the pH by delivering a sulfur.
If the soil is acidic, then we will increase its pH by delivering an oyster shell flour. (These will be done by using a servo as a container opener)
We will use Arduino R3 and a pH sensor. However, I have been worrying about the pH sensor probe since most blogs I have seen said that it is fragile.
Is there an idea that you can tell me so that we will be able to clearly make our project? I will accept any suggestions and it will help me and my team.
To be specific, our aim is to use a pH sensor to monitor Soil pH for a long time and to neutralize its pH level.
Thank you so much. I'm looking forward to receive your ideas and suggestions!
our aim is to use a pH sensor to monitor Soil pH for a long time
pH probes are very delicate and need to be very frequently cleaned and calibrated. People who care about accurate data calibrate their probes using pH standards before every measurement session.
The probes are not suitable for use as long term monitors of soil pH nor is there any need to do so. Soil pH does not need to be frequently adjusted. You make a measurement, make a trial adjustment, mix the sample well and then repeat the test.
Reaction time of the pH of the soil when using sulphur or calcium carbonate for adjustment will be in the order of days, depending on things like how well you mix the soil, water it (or rain), and other mineral contents of the soil. This as soil by nature does not mix by itself much if at all.
Normal pH probes are not suitable to just ram into the ground and take a reading with. It just doesn't work like that with soil. This is a lab type test, where you have to take a sample and test it.
Did you find a solution for this ?
I was thinking in a similar project but using a comparison between two pH sensors Gravity™ Analog pH Kit | Atlas Scientific, in a liquid media.
Having one value as input and one value as output by watering the whole sample. It'll depend on which type of sample are you working with, and it'll be a destructive test as well.
Very interesting project but perhaps a real challenge. Most pH measurements are liquid based and I'm wondering if there is a way to measure soil ph with a simple probe.
According to this site
"Another pH value measurement possibility is amperometry. The advantage of amperometry as a pH measurement method is that it is simple to use. In amperometric pH measurements hydrogen generation occurs on a noble metal. When combined with a less noble metal a power distributing galvanic cell is formed. Because hydrogen ions are generated the cell's current depends on the pH value. The disadvantages of this method is that differences in the sample composition create very large errors in pH measurements and the method cannot deliver dependable results in extremely concentrated acids and bases due to effects related to the pH glass membrane.
In special cases the pH value measurement can be made using conductometry (conductivity measurement). With this pH measurement method any membrane effects are minimized because of the measurement technique. The advantage of this pH measurement method is that it is relatively easy to use. The disadvantage is that a conductivity measurement measures all ion activity not just hydrogen ion activity. Additionally this pH measurement is only reproducible and safe at low ion concentrations."
You would need to look into this but it may be possible to do this with a system similar to one of my own projects described here - measuring soil conductivity