Comparing Handheld Meters and Electronic Dosimeters for Measuring Ultraviolet Levels under Shade and in the Sun

Abstract

This study aimed to compare the validity, reliability and practicality of alternative portable methods for measuring erythemal UVR levels in passive recreation areas in public parks. UVR levels were measured for point in time comparisons between Solarmeter 6.5 handheld meters and time-stamped electronic dosimeters in a large central park in Melbourne, Australia. Observations were made at 20 locations in the park by two research assistants under two conditions: (1) matched shade (2) contrasting shade-no shade. Comparisons were also made with scientific instruments on the UVR monitoring station rooftop and by remotely selecting UV records and forecasts on cloud-free dates of park observations. There was good agreement between the portable UVR instruments in the park setting as confirmed via Bland Altman plots, while the dosimeter appeared less sensitive to change in shade conditions. The rooftop measurements showed that the Solarmeter 6.5 UVR readings were comparable to those of the adjacent rooftop instruments. The practicalities of using the dosimeters and Solarmeters for behavioral studies are discussed. These findings provide a basis for use of the Solarmeter 6.5 to measure changes in UVR levels due to different environmental conditions with relative accuracy for intervention studies in outdoor settings.

Figure 1

(a) Mean UV Index of handheld 1 and dosimeter 3. (b) Mean UV Index of handheld 2 and dosimeter 4.

Figure 2

Inter-rater agreement under shade.

Figure 3

Handheld meter and dosimeter agreement measuring reduced UV sun to shade.

Figure 4

Agreement of handheld meter and dosimeter to ARPANSA spectroradiometer (unshaded conditions).

Figure 5

Australian radiation protection and nuclear safety agency (ARPANSA) rooftop UV measurements across the day for the Solarmeter 6.5 compared with the spectroradiometer and Biometer. The agreement between the two Solarmeters and the ARPANSA SRM and Biometer is mostly between 5 and 10%.