Rainwater tank level measurement
I have been searching for suitable non-contact ultrasonic sensors, that could be used for monitoring the water level through Loxone. I found a few that do have the 0-10V output, which is easy to connect into Loxone analog input.
- UB2000-F42-U-V15 (~220€, range 60...2000mm)
- UB4000-F42-U-V15 (~240€, range 200...4000mm)
- UB6000-F42-U-V15 (~270€, range 350...6000mm)
- ULM-53 (~300€, range varies based on the model from 0.1 ... 1 m; 0.2 ... 2 m; 0.2 ... 6 m; 0.4 ... 10 m; and 0.5 ... 20 m. See datasheet on the web of the manufacturer)
The last option was quite nice surprise to find, and is probably the most interesting one.
Here I am not aiming to serve a complete product market research, nor have I studied all the documentation for available product, but the last product seems to be be able to calibrate/map the water level limits to 0..10V. This achieves a truly accurate measurement, because the voltage range on output will fully cover the working range of the water levels in the given tank.
I have ordered this Level sensor from AliExpress, it should arrive every moment. I will post an update once tested.
The water level sensor has just arrived. I am looking forward to test it. It should work with 12- 36 VDC, and the output is 0-10V which is great. Based on my request, the scale is from 0 to 1 meter water depth, which is OK for my tank with dept of 130 cm and water overflow is at 108 cm. I am really excited to try this.
Now I was a bit afraid, how can this be measuring water level based on the pressure at the bottom of the tank, if the sensor is isolated there with no reference to atmospheric pressure. But the reference point here is not vacuum here, it is the atmospheric pressure. And guess how they did that. There si a tiny red pipe in the cable where the atmospheric pressure goes in and where the sensor gets the reference. I will post more details once I install and test this sensor.
I have to say, I am very happy with the pressure water level sensor. More details are in my blog post.