images

[kriswiner]

[kriswiner]

[kriswiner]

[kriswiner]

[k-kwan]

Hello, may I ask where I can get the Arduino RTC library files from

[kriswiner]

They are part ofthe Arduino core for the Ladybug (STM32L432KC) development board written by Thomas Roell (grumpyoldpizza) on github. Or see Ladybug product page on tindie.com for more links.

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On Sat, Jul 20, 2024 at 10:56 AM k-kwan ***@***.***> wrote: [image: AS7331 设置] <https://user-images.githubusercontent.com/6698410/215298161-abc613b3-15e3-4a7d-9e9e-55e6fc9d6ac8.jpg> Hello, may I ask where I can get the Arduino RTC library files from — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKTAZPXVYZVXZHUUPBTZNKCELAVCNFSM6AAAAABLGBHNOOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENBRGE4TCMBZGI> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[matthiasbirkich]

Dear Kris Winer,
thank you for your code and your work to get reliable irradiance values for UVA, UVB and UVC with the AS7331 sensor.
The idea to look for a recalibration by using an UVC LED is great! In my institute for Tropical Marine Research we are going to use this sensor for measuring the irradiance of UV-LED-lamps.
I calculated the irradiance from one LED which is from ams osram (OSLON UV - SU CULBN2.VC-AGAN-67-4E4G).
The radiant flux of the LED is like yours φe = 5.2 mW. The formula for a lambertian light source to go for irradiance is:
E [W/m2] = φe / 4πr^2 (correct?)
Than the irradiance in a distance of 10cm = 0.1m is calculated to
0.0052W/(4π * 0.1^2) = 0.041 W/m^2 = 4.1 µW/cm^2

When I checked your calculation on tindie there is a difference according to the formula I found in wikipedia and on chatgpt:
Kris Winer: “Of course, I measured essentially zero with the led off. At 10 cm distance, 12 uW/cm^2 indicates a source of 12 x 4/3 x pi x 100 uW ~ 5 mW, just what it should be.”

Are you so kind enough to explain to me your equation, because your measured value is three times higher as my calculation and your calculation is not enough transparent to me.
Thank you very much for your help, Sir!

Best regards
Matthias

[kriswiner]

I think mine is in error...Area should have been 4 pi^2 not 4/3 pi^2...

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On Sun, Sep 29, 2024 at 1:39 PM Matthias Birkicht ***@***.***> wrote: Dear Kris Winer, thank you for your code and your work to get reliable irradiance values for UVA, UVB and UVC with the AS7331 sensor. The idea to look for a recalibration by using an UVC LED is great! In my institute for Tropical Marine Research we are going to use this sensor for measuring the irradiance of UV-LED-lamps. I calculated the irradiance from one LED which is from ams osram (OSLON UV - SU CULBN2.VC-AGAN-67-4E4G). The radiant flux of the LED is like yours φe = 5.2 mW. The formula for a lambertian light source to go for irradiance is: E [W/m2] = φe / 4πr^2 (correct?) Than the irradiance in a distance of 10cm = 0.1m is calculated to 0.0052W/(4π * 0.1^2) = 0.041 W/m^2 = 4.1 µW/cm^2 When I checked your calculation on tindie there is a difference according to the formula I found in wikipedia and on chatgpt: Kris Winer: “Of course, I measured essentially zero with the led off. At 10 cm distance, 12 uW/cm^2 indicates a source of 12 x 4/3 x pi x 100 uW ~ 5 mW, just what it should be.” Are you so kind enough to explain to me your equation, because your measured value is three times higher as my calculation and your calculation is not enough transparent to me. Thank you very much for your help, Sir! Best regards Matthias — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTDLKQQMCESWMVK666CEMLZZBQPTAVCNFSM6AAAAABLGBHNOOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGOBRGU4TIOBTGY> . You are receiving this because you authored the thread.Message ID: ***@***.***>