Optical Density measurement Ideas?

[ali_asadzadeh]

Hi,
I was wondering if it's possible to measure Optical Density with these Color sensors, like ISL29125? is it possible? what's the formula to convert the reading to OD? any other ideas are welcome

[Kleinstein]

To measure optical density it still needs a light source and some optics. As most light sources are not that stable it may take a way to switch between the sample and a transparent light path. With lower accuracy an LED might be considered stable enough over a short time (e.g. a few minutes).

In photography OD is defines as  log_10 of the intensity ratio due to absorption.

[ali_asadzadeh]

Thanks, So How should I calculate intensity? Should I use this formula to calculate the intensity?   intensity =SQRT((R^2+G^2+B^2 ))

[jprozas]

Luminance Y

Y = R*0.3+G*0.59+B*0.11


https://www.scantips.com/lumin.html

[ammjy]

might be, it will help to you ?
for measure fluide level. i used photodiode and LED light.
(elementry class !! haha)

in result. most big problem was the control variables of materials ( for example, Light reflection of material, surface of material things.. )
(actually i didnt calculate.)

in pictures. for fluid sample. i used coke.(it was bad choice)
character of photodiode really well reciving effect from temp..
LED temp is really hot.

[texaspyro]

Most OD measurements and devices require a very large dynamic range (>20 bits is not unusual) and most color sensors do not come close to being able to do that.

[ali_asadzadeh]

Thanks for the updates,

Most OD measurements and devices require a very large dynamic range (>20 bits is not unusual) and most color sensors do not come close to being able to do that.

The new ones have 16bit's of Res, But do you happne to know what devices they use that have more than 20bit?

[ajb]

What range of OD do you want to measure?  If you want a range of three steps, that's a ratiometric range of 1000, so ten bits right there, assuming your sensor is linear.  You'll need ~3.3 bits per OD step just to have the dynamic range.

[texaspyro]

Thanks for the updates,

Most OD measurements and devices require a very large dynamic range (>20 bits is not unusual) and most color sensors do not come close to being able to do that.

The new ones have 16bit's of Res, But do you happne to know what devices they use that have more than 20bit?

The high dynamic range / lab quality units don't use integrated color sensors.   They use individual light sensors and ADC chips.