Determination of Cloud point in liquid mixtures

Other Hardware Sensors
1

Hi all,

I would like to develop a cloud point detector in liquid mixtures, using a small laser pointer (visible light, 1mW) as a light source and a photo-diode as a light detector that has to be interfaced to a PC for light intensity reading. When increasing temperature of a liquid mixture, at a given temperature, opalescence occurs dropping trasmission of light (several 10%s drop) . This phenomenon can be detected using the mentioned setup. Optionally it would be great if the same hardware could control not only laser ON/OFF and photodiode reading, but also storing of the photodiode reading in a PC and controlling and reading the temperature (e.g. interface with a water bath).
I looked around in the literature and got through Arduino devices that might be smart ways to develop such a device.
First, I would like to check if anybody is aware of a similar device already developed.
Alternatively can somebody suggest the best devices (including the various Arduino hardwares) that could be used for this task? How to interface laser/photodiode/PC through Arduino?
I have no experience with such hardware.

Thanks a lot for your attention.
Best regards, Alessandro

2

if I understand your setup correctly an Arduino UNO could do the job

  • Arduino UNO

  • one pin to control the laser (needs a power transistor)

  • one pin to control the heater (needs a power transistor)

  • one pin to read the temperature - check the DS18B20, 0.1 degree , watertight versions available.

  • one pin to read the photodiode -

  • an I2C display to show the temperature and the value of the photodiode (%%)