Wearable Spectroradiometer for Dosimetry

Abstract

Available wearable dosimeters suffer from spectral mismatch during the measurement of broadband UV and visible radiation in environments that receive radiation from multiple sources emitting differing spectra. We observed this type of multi-spectra environment in all five Washington State cannabis farms visited during a field study investigating worker exposure to ultraviolet radiation in 2018. Spectroradiometers do not suffer from spectral mismatch in these environments, however, an extensive literature review conducted at the time of writing did not identify any spectroradiometers that were directly deployable as wearable dosimetry devices. To close this research gap, we developed a microcontroller system and platform that allows for researchers to mount and deploy the Ocean Insight Flame-S Spectroradiometer as a wearable device for measurement of UV and visible wavelengths (300 to 700 nm). The platform validation consisted of comparing measurements taken under platform control with measurements taken with the spectrometer controlled by a personal computer running the software provided by the spectroradiometer manufacturer. Three Mann-Whitney U-Tests (two-tailed, 95% CI), one for each intensity condition, compared the central tendency between the total spectral power (TSP), the integral of a spectrum measurement, measured under both control schemas. An additional analysis of per pixel agreement and overall platform stability was performed. The three Mann-Whitney tests returned no significant difference between the set of TSPs for each filter condition. These results suggest that the spectroradiometer takes measurements of equivalent accuracy under both control schemas, and can be deployed as a wearable device for the measurement of wavelength resolved UV and visible radiation.

Keywords: dosimetry; environmental monitoring; sensor applications.

Figure 1

A top view of the wearable platform with hood open.

Figure 2

A simple block diagram of the testing setup.

Figure 3

Each chart displays an average spectrum created by averaging three repeat spectral measurements. The top row shows the average spectrum of the platform-controlled measurements, and the bottom row shows the average spectrum of the OceanView controlled measurements.

Figure 4

Scatterplots of measurements taken during OceanView control on the x-axis and platform control on the y-axis, both in units of µW/nm × cm², for the three cycles. The plots also show the linear regression line, equation, and correlation coefficient.

Figure 5

The slope of linear regressions for each pixel computed using three data points corresponding to platform- vs. OceanView-controlled measurement during each of the three filter conditions.