The UV Spectra Database Explorer evaluates the 54 measured spectra of the Opsytec spectral database: select UV lamps and UV LEDs, overlay them in the chart and compute every radiometric, photometric and photobiological quantity in one go. These include irradiance Ee, the shares in UV-C, UV-B, UV-A2, UV-A1, in the visible range and in the IR according to CIE, peak and centroid wavelength, FWHM, the ozone-forming share below 240 nm, illuminance, chromaticity coordinates, correlated colour temperature and colour rendering index Ra, as well as the weighted quantities for actinic UV hazard, blue light hazard, microbicidal effect on B. subtilis spores and on MS2, erythema, vitamin D synthesis and melanopic effect — each with the permissible exposure time and with the dose for a freely chosen exposure duration. Every spectrum can be scaled to a target value, for example 10 W/m² in the UV-A, so that lamp types can be compared at the same irradiance. Own measurements as .spec, .isd, CSV, TXT or XLSX can be added and evaluated with the same formulas; they are processed exclusively in the browser memory and are never stored. The results can be exported as a CSV table or as a PDF report. The calculated values are for orientation — only a measurement with a calibrated spectroradiometer is binding, such as those Opsytec Dr. Gröbel builds and calibrates in its own calibration laboratory.
Every selected spectrum yields the same set of quantities — for database spectra and for your own measurements alike:
The values appear as tiles for the lead curve and as a comparison table across all selected spectra; both can be exported as a CSV file or as a PDF report.
All integrals are formed with the trapezoidal rule on the native measurement grid of the spectrum. The action spectra are interpolated linearly onto that grid and set to zero outside their domain; the spectrum itself is never resampled. If the measured range does not fully cover the domain of an action spectrum, the Explorer flags the affected quantity.
The band limits follow the CIE definition: UV-C 100–280 nm, UV-B 280–315 nm, UV-A2 315–340 nm, UV-A1 340–400 nm, UV-A 315–400 nm, visible 380–780 nm, IR above 780 nm. Photometric and colorimetric quantities come from V(λ) per CIE 1924 / ISO 23539 and the CIE 1931 (2°) colour matching functions: Ev = 683 lm/W · ∫ E(λ) · V(λ) dλ. The correlated colour temperature follows from the smallest distance to the Planckian locus in the CIE 1960 uv plane and stays empty when the chromaticity lies too far from it — which is the rule for excimer lamps and narrow-band LEDs. The colour rendering index Ra follows CIE 13.3-1995 with eight test colour samples, von Kries adaptation and U*V*W*.
The photobiological quantities use S(λ) per ICNIRP / EN 14255-1 / EN 62471 (actinic, limit 30 J/m²), the UV-A limit of 10 000 J/m², B(λ) per EN 62471 (blue light, 100 J/m²), the erythema action spectrum per ISO 17166 / CIE S 007, the vitamin D action spectrum per CIE 174:2006, the melanopic action spectrum per CIE S 026:2018 and two separate microbicidal action spectra: sbakt(λ) for Bacillus subtilis per Cabaj et al. 2002 (Water Supply 2(3), 175–181, 200–400 nm) and sMS2(λ) for the enterobacteriophage MS2 per Beck et al. 2015 (Water Research 70, 27–37, 200–300 nm) — both normalised to 253.7 nm, but not interchangeable. Which function is stored with which source and domain is shown by the “Calculation basis” card in the app. Opsytec explains the underlying quantities under radiometric quantities and photometric quantities.
Besides the database spectra, your own measurements can be loaded and evaluated with the same formulas: .spec from the Opsytec SRpro software, .isd from SpecWin, and tables as .csv, .txt, .dat or .xlsx. For tables the Explorer detects the separator, the decimal mark, the wavelength column, the value columns and the unit on its own; if a file holds several value columns, each column becomes its own spectrum. Recognised units range from W/(m²·nm) through mW/cm²/nm to µW/cm²/nm, including the notation W m-2 nm-1.
Files are processed exclusively in the browser memory: nothing is transferred, nothing is stored, and reloading the page discards the measurements. Loaded spectra sit alongside the database spectra in the chart, in the comparison table and in the PDF report.
The database spectra were recorded at the measuring distance of the calibration laboratory; their absolute values therefore depend on distance and sample. To compare lamp types, every spectrum can be scaled to a target value — for example 10 W/m² in the UV-A or 1 mW/cm² in total. The Explorer then converts all values proportionally: shares and colour values stay unchanged, while irradiances, doses and permissible exposure times follow the target value.
The exposure duration set yields the radiant exposure He = Ee · t and the weighted doses. Conversely, the permissible exposure time shows after which time the respective limit would be reached. These values are guidance for the design; assessing a workplace calls for a measurement per EN 14255-1 — with a radiometric UV sensor or a spectroradiometer. For UV disinfection systems, Opsytec summarises the requirements under safety of UV disinfection.
The database holds 54 typical spectra from 15 lamp classes:
Several selected spectra are overlaid in the chart — with “peak = 1” to compare the shape, or scaled to a common target value for the energetic comparison. The raw data of all spectra can be downloaded from the spectral database for UV lamps and UV LEDs.
The spectra are typical samples of their lamp class, measured in the calibration laboratory of Opsytec Dr. Gröbel GmbH according to CIE 250:2022. Sample spread, ageing, operating temperature, ballast and measuring distance change the absolute irradiance and — to a lesser extent — the spectral distribution. The calculated values are for orientation, not for acceptance testing.
In detail: quantities whose action spectrum reaches beyond the measured range are flagged; the colour temperature is omitted for chromaticities far from the Planckian locus, and Ra is marked as not applicable once |Duv| exceeds 0.0054. Binding values come only from a measurement with a traceably calibrated instrument — such as the SR900 spectroradiometer or the RM-12 UV meter, calibrated in the UV laboratory of Opsytec.
The dose is the product of irradiance and time: H = E · t. The Explorer integrates the irradiance in the desired band from the spectrum; the exposure duration is set on the left. For weighted quantities — actinic, erythemal, vitamin D — the spectrum is first weighted with the action spectrum, then integrated and only afterwards multiplied by the time.
It states after which time the respective limit would be reached: 30 J/m² for the actinic effective exposure per EN 14255-1, 10 000 J/m² for unweighted UV-A and 100 J/m² for the blue light hazard per EN 62471. The figure applies to the selected spectrum at the displayed irradiance and does not replace a risk assessment.
Yes. The Explorer reads .spec, .isd, CSV, TXT and XLSX files directly in the browser; the file never leaves your computer and is not stored. Reloading the page discards it.
The correlated colour temperature is only meaningful when the chromaticity lies close enough to the Planckian locus. For UV sources, excimer lamps and narrow-band LEDs it does not — the Explorer then shows N/A instead of a meaningless number. For the same reason the colour rendering index is marked as not applicable once the distance to the locus becomes too large.
They are absolute in W/(m²·nm), measured at the measuring distance of the calibration laboratory. Because that distance does not suit every application, each spectrum can be scaled to a target value; the spectral shape stays unchanged.
Because they describe different test organisms and therefore give different results. sbakt(λ) stands for spores of Bacillus subtilis, the test organism of biodosimetry; sMS2(λ) stands for the enterobacteriophage MS2, the surrogate used to validate medium-pressure systems. Both are normalised to 253.7 nm and agree there by definition — but not at other wavelengths: at 222 nm sMS2 is 2.09 while sbakt is 0.90. A 222 nm excimer source thus acts on MS2 more than twice as strongly as the same irradiance at 254 nm, but slightly less strongly on B. subtilis spores. The Explorer therefore reports both evaluations separately. Neither curve can be transferred to other organisms.