Light Sensor Scale

Does anybody happen to know what scale the U506 light sensor uses? Is it measuring DLI?

It’s measuring light energy received, in watts per metre squared.

You can see it if you run

dhub list /app/light/value

root@swi-mdm9x28-wp:~# dhub list /app/light/value
value <input> =
      data type = numeric
      units = 'W/m2'