## Calculating the light intensity by wevelength with TSL2591 Moderators: adafruit_support_bill, adafruit

Calculating the light intensity by wevelength with TSL2591

Hello.

I am interested in measuring light intensity by light wavelength.

I searched the internet to find out which sensor would be appropriate for my measuring project.

I found a TSL2591 sensor module, and faced some problems.

There was a thread about what IR and Visible number mean at viewtopic.php?f=22&t=76089&p=534825&hilit=tsl2591

So, I thought if adafruit provides the data used in figure 12 graph (Spectral Responsivity) in datasheet page 8, I could make my measuring project more precisely. If anyone who have the data for this graph, please upload the data. :)

figure 12 graph.PNG (86.14 KiB) Viewed 159 times

For example, if wavelength is 700nm, and a Visible number from the sensor is 300, light intensity (even though it will be a not absolute number) will be 300/0.95. And 0.95 is a number I read approximately from the figure 12 graph in datasheet PDF(https://cdn-shop.adafruit.com/datasheet ... _EN_v1.pdf).

Thank you.

kungmo

Posts: 2
Joined: Mon Aug 13, 2018 1:05 am

Re: Calculating the light intensity by wevelength with TSL25

So, I thought if adafruit provides the data used in figure 12 graph (Spectral Responsivity) in datasheet page 8, I could make my measuring project more precisely. If anyone who have the data for this graph, please upload the data. :)

The actual TSL2591 chips are manufactured by AMS in Austria. They may be able to provide you with the data behind the graph - although I suspect it represents 'typical' data from a number of chips.
https://ams.com/tsl25911

Posts: 73210
Joined: Sat Feb 07, 2009 10:11 am

Re: Calculating the light intensity by wevelength with TSL25

So, I thought if adafruit provides the data used in figure 12 graph (Spectral Responsivity) in datasheet page 8, I could make my measuring project more precisely. If anyone who have the data for this graph, please upload the data. :)

The actual TSL2591 chips are manufactured by AMS in Austria. They may be able to provide you with the data behind the graph - although I suspect it represents 'typical' data from a number of chips.
https://ams.com/tsl25911