Solar Light Company - PMA 2105 Detector

UVB Detector with Beam Splitter Adapter

The PMA2105 detector gives an accurate measurement of biologically weighted ultraviolet radiation from Solar Simulators manufactured by Solar Light Co.

FEATURES

	Dynamic range 2*10⁵
	Excellent long term stability
	NIST traceable calibration
	Radiometric and biological units
	Dose controller functionality

Special mounting hardware allows direct coupling with beam splitter available for 16S Solar Simulators.

The detector’s spectral response follows closely the erythema action spectrum (Fig.1.)[1]. Due to built-in Teflon diffuser the detector has negligible azimuthal error making the measurement insensitive to the rotation of the detector. Extended measurement range of 600 MED/Hr enables measurement of intense radiation.

APPLICATIONS

	Skin and SPF testing
	Clinical studies
	In-vitro testing
	Phototherapy
	Photobiology
	Material testing
	Chemistry laboratories

In conjunction with the Solar Simulator and XPS200 Xenon Lamp Power Supply the PMA2100 with the PMA2105 detector can operate as a smart dose controller/monitor substantially enhancing the functionality of the Solar Simulator.

The measurement result can be shown in MED/Hr, µW/cm² as well as a time to accumulate 1 MED. High dynamic range of the detector allows measurements down to 0.1 µW/cm² with the ability to measure radiation as strong as 3.5 mW/cm².

The biologic effectiveness of ultraviolet radiation is strongest for wavelengths between 280 to 320 nm, classified as UV-B by the CIE. Several biologic action spectra, functions relating wavelength and the biologic effectiveness, are shown in Figure 3. The most commonly used, erythema action spectrum [1], also referred to as CIE 1987 action spectrum, represents the sensitivity of human skin to sunburn.

Other biologic action spectra also exhibit rapid decline in UV effect with an increase of wavelength over the UV-B range. In general the reading of an erythemally weighted detector cannot be directly interpreted as biological effectiveness other than erythemal. However, there are ways to make the necessary correction numerically [2].

The biologic effectiveness of the UV radiation can be measured in terms of effective irradiance in radiometric units, for example [µW/cm²]. It is often related to the sensitivity of the human skin to sunburn and expressed in Minimal Erythemal Doses per Hour [MED/Hr]. One MED is the effective UV dose capable of causing minimum redness (erythema) in an average number 2 skin. Based on a study [3], the relationship between MED/Hr and radiometric units was assumed:

1 [MED/Hr] = 5.83 [µW/cm²]

This formula is programmed into the PMA2105 detector allowing for easy conversion of units. Consequently, the integrated effective dose can be expressed in [mJoules/cm²] or MED.

Many sources produce UV radiation with a spectral irradiance changing rapidly over narrow wavelengths range. Spectral irradiance of the solar UV is an extreme example of such steep slope due to the UV-B and UV-C absorbing ozone layer.

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Figure 3: Selected Biologic Action Spectra

SPECIFICATIONS

Spectral response	Follows erythema action spectrum Figure 1
Range	600 [MED/Hr], 3.5 [mW/cm2]
Display resolution	0.01 [MED/Hr], 0.1[µW/cm2]
Operating environment	32 to 120 °F (0 to +50 °C) no precipitation
Temperature coefficient	1% /°C
Cable	1ft, retractable to 5ft (0.3m/1.5m)
Diameter	1.6" (40.6 mm)
Height	1.8" (45.8 mm)
Weight	7.1 oz. (200 grams)

Analog versions of this detector are available See PMA1105

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