EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: bypassrestrictions on January 29, 2022, 04:46:51 pm
-
Can I make a UV-C sensor with Arduino or something else?
UV sensor in water purifier has failed, I'm thinking of ways to trick the PCB into thinking it is working and make the water purifier work. Company is saying it is an old model and they are not making spares for it. I don't think I can buy a new one any time soon.
But the problem I'm facing now is to tell if the UV-C light is working or not, UV sensors or UV LDRs are not sold where I live and I cannot buy them online.
But Arduino are sold here, small UV modules for it are also available, is there anything I can make to regularly check if the UV-C light in the water purifier is working or not? And it indeed is a UV-C light and not normal light?
-
There are UV sensors, even Amazon has them. I don't know why they would be hard to get it India but I suppose there could be problems in shipping.
https://www.amazon.com/200nm-370nm-Wavelength-UV-Sensor-Ultraviolet/dp/B00NL9XNN8 (https://www.amazon.com/200nm-370nm-Wavelength-UV-Sensor-Ultraviolet/dp/B00NL9XNN8)
I see similar parts on the Amazon.in site. Just be sure the sensor covers 200-280 nm wavelengths if you want to include UV-C
I have no idea how this could be integrated into the system.
Wouldn't it be easier to just measure the current through the LED (maybe measure across any limiting resistor or even the forward voltage drop of the LED itself. If there is current flow through the LED, it is very likely emitting.
-
There are UV sensors, even Amazon has them. I don't know why they would be hard to get it India but I suppose there could be problems in shipping.
https://www.amazon.com/200nm-370nm-Wavelength-UV-Sensor-Ultraviolet/dp/B00NL9XNN8 (https://www.amazon.com/200nm-370nm-Wavelength-UV-Sensor-Ultraviolet/dp/B00NL9XNN8)
I see similar parts on the Amazon.in site. Just be sure the sensor covers 200-280 nm wavelengths if you want to include UV-C
I have no idea how this could be integrated into the system.
Wouldn't it be easier to just measure the current through the LED (maybe measure across any limiting resistor or even the forward voltage drop of the LED itself. If there is current flow through the LED, it is very likely emitting.
Those were the sensors I was talking about, I just don't know how to integrate them into an Arduino, I cannot use those modules as UV sensor in the water purifier.
Measuring the current through the bulb would just let me know if it is working, but it would not tell me if the bulb is emitting the UV-C light or not.
-
You may find this project helpful. This one is about UVC measurement using Arduino. https://hackaday.com/2020/03/27/measuring-uv-c-for-about-5/
-
Nearly any photodetector will probably work. If the bulb is lit it is emitting UV-C, what other wavelength would it emit if it wasn't emitting UV-C?? They simply have less output as they age. It is basically a mercury vapor fluorescent lamp without the powder coating to make visible light. What was the original detector, some type of LDR? You should be able to fake it out with just a resistor. These units aren't very complex. There should be a purple or blue tinted window to visibly show that the lamp is lit.
-
Nearly any photodetector will probably work. If the bulb is lit it is emitting UV-C, what other wavelength would it emit if it wasn't emitting UV-C??
Plenty of red, blue and visible violet.
A common failure mode of fluorescent lamps, which no doubt also applies to low pressure mercury discharge lamps, which emit UVC, is depletion of the mercury, leaving only argon and neon left. This results in a pink light and the phosphor not emitting much light, because the UV emission of the arc falls.
-
Honestly with something this important I'd just find a way to buy a new UV water sterilizer. You apparently have issues with sourcing parts and then not understanding how to integrate them is a bigger issue, given this reality I'm not sure how you would validate that the unit is even working. By the way it needs to work continuously and be able to recognized partially failing UV tubes. Generally the tubes used in these systems (assuming tube based systems) degrade over time. By the way UV sensors also degrade over time.
The ones that I have worked on have also gone obsolete but the supplier / manufacture offered a rather simple upgrade path with a new controller. You might want to consider seeing what upgrades are available. Come to think of it I'm not even sure how the company monitors the UV bulb with their controller, they do but it might be a current based monitoring.
A few years back I did a search For sensors to monitor another system that used UV and frankly it was rather difficult to find anything that I would call reliable and inexpensive at the same time.
-
welcome my friend
You can buy a 220-volt water purification sensor, and you can use a relay to program it with Arduino.
Not everything is looking for the little ingredients
The best components that operate at a high voltage so that the circuit is of high accuracy