Nitrameter on a microcontroller

Question

Arduino

Recently, all kinds of sensors for monitoring the state of the environment have become very popular.
In particular, all kinds of nitrates are gaining popularity. The sensor itself looks very simple. Something like a mono plug for 3.5mm headphones. I stuck one in a tomato and the result is visible on the screen. But here the prices start from 5000r.

Actually the question is, is there really such a complex logic inside, or is the sensor itself so complex and actually not as simple as it seems. Is it really impossible to make such a device yourself, let's say on Arduino?

There are more or less similar sensors in the form of 2 nails that measure soil moisture, you can probably use a headphone plug, you just need to work out the logic for polling such a sensor.

Answer 1

Here is the manufacture of a homemade nitrate indicator. Also there is a link to a forum with a discussion of the design.

Answer 2

Easy. This is the only topic of the dissertation. It is necessary to study on a large static material the dependence of the conductivity of the contents of a tomato on the amount of nitrates in it. And for use not only with tomatoes, you also need to develop calibrations.