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Topic: Water Color Sensor (Read 123 times) previous topic - next topic

MarcSparck

Jan 11, 2017, 09:01 pm Last Edit: Jan 11, 2017, 09:26 pm by MarcSparck
Hey there,

I am thinking about a little machine for Titration. I need a color sensor which can measure the color of water in a jar because the machine should pump an indicator in the water until the color changes from clear to orange/red and then stops. Does that work with an TCS34725 or something similar? I dont think that this cheap sensor can measure the color of the water, so maybe someone has experience with that and can help me?

Thanks for your help!  :)


Arctic_Eddie

A color camera like the Arducam OV7670 series.

Delta_G

A diffraction grating and a photodiode array is what I used for something similar. I also had a mirror to help focus it but I don't know that it was critical.
Ad hoc, ad loc, and quid pro quo.  So little time - so much to know!  ~Jeremy Hillary Boob Ph.D

Paul_KD7HB

Hey there,

I am thinking about a little machine for Titration. I need a color sensor which can measure the color of water in a jar because the machine should pump an indicator in the water until the color changes from clear to orange/red and then stops. Does that work with an TCS34725 or something similar? I dont think that this cheap sensor can measure the color of the water, so maybe someone has experience with that and can help me?

Thanks for your help!  :)


Hi, MarcSpark. Good question!
I am reminded of a device my wife used 55 years ago in a hospital lab. Titration color density is really based on a person's experience. The hospital needed consistency and they had a device that passed a white light through the solution and then through a filter colored the same as the indicator in the solution. Then a photo cell determined the amount of light through the filter. Or something like that.

Your sensor might work is you used a color filter to match the indicator material.

Paul

xpress_embedo

I am also working on color sensor and using TCS3200 color sensor, it works fine but the range of the sensor is very less and if the distance of is changed you need to re-calibrate the sensor. I am working on a solution for this.

The sensor TCS34725 is an upgraded version of the sensor which i am using.

If somehow you place the sensor below the jar (this will make the distance same always), and calibrate the sensors for different colors you want to sense, i think this approach can work for you application.
Just try it and share the results.

MarcSparck

#5
Jan 13, 2017, 09:48 pm Last Edit: Jan 13, 2017, 10:00 pm by MarcSparck
Hey,
thanks for all your helpful answers!
I combined your ideas and thats what I am currently doing:
I passed a white light through the jar. On the other side of the jar is a TCS230 sensor. So the light gets filtered while passing the water and then the sensor can measure the color. I tested it and it worked pretty well, but I have to test it a bit, because it doesnt work every time, e.g. when the water or the jar is dirty.

The camera is also a nice idea to check or to take an photo of each jar after measure.

Thanks for your answers, you helped me very much!  :)  :)


P.S. Here is a picture from my first test

Arctic_Eddie

The camera has the advantage that it can be made to focus on the liquid within the container. This reduces the problem of light reflections from the outside surface of the container. In practice, you would take a photo of the liquid at the beginning and record the RGB levels. Thereafter, you would continue taking photos and look for a change in the levels that indicate a shift toward the indicator color. Almost any color camera will work as long as you can communicate with it via the Arduino. There are some that use serial connections. Check Adafruit and Sparkfun but I suspect that one of the Arducams will be more cost effective.

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