Calibration sheets for pyranometer 840487

The Kipp & Zonen CM11 (serial number: 840487) was used to measure GHI from 2015 (probably earlier also until)

There is one calibration sheet from Kipp & Zonen from March 1984 (sensitivity: 4.98).

Elsa's logbook notes the following:
> 13/5 2015 CM11 til globalstråling er kalibreret til 5.065 microV/W/m2 (tidligere 4.98 microV/W/m2) (1.8% change).

No target file, test, or entry point is named. Review the repository's weather-data content structure and determine where the CM11 calibration record for serial 840487 belongs, using the 1984 calibration sheet and 2015 logbook note as source material. Done means the relevant calibration information is recorded in the appropriate project location.

Written by the indexing model from the issue text.