We are using a humidifier from Stadler Form, model is Oskar. Whenever the water level drops below a certain level the humidifier will stop circulating the air and a led light will turn on.
Is there a sensor available that I could connect to the wires running to the led and measure whether there is voltage measured or not?
The expected outcome of the sensor would be:
When voltage/current is measured then water needs to be replenished
When there is no voltage/current measured then water level is OK
Hope someone has an idea on what sensor to use or another way to measure this.
I would suggest using a different method, connecting to the LED wires may not be safe.
There are several options:
an Aqara water leak sensor with some wires attached to it, very much like this project.
an Aqara window/door sensor on the outside of the water container and some sort of floating device on the inside, where the floating device will hold the magnet. When the water level reaches the required minimum level, the magnet will trigger the sensor. This may require some custom 3D printing though.
alternatively, using a water float switch (can be bought for cheap on Aliexpress) combined with the door/window sensor. See this project.
He could modify a window contact so that he soldered a cable to each reed contact.
It is then sufficient to connect it to a rain sensor.
As soon as water touches the sensor, the window contact closes. When the water sinks below the sensor, the window contact opens.
A few flows and the problem is solved.
I think you will soon have issues with oxidation of the copper.
These sensors are not design for continuous contact with water.
(Many even are heater to evaporate the water so it also properly detects when the rain stops)