UVpad – spectral UV measurement in pocket format
The UVpad is an autonomous, spectrally measuring UV radiometer for UV belt systems. It resolves the radiation from 200 to 440 nm ± 5 nm at a spectral bandwidth of 2 nm and measures irradiances from 2 to 5000 mW/cm², optionally 25 to 35,000 mW/cm². Because it works without optical filters, different lamp types and UV LEDs can be compared directly; at a height of 14.4 mm it travels through the system.
The UVpad is the world‘s thinnest autonomous spectrally resolving UV radiometer. It combines scientific measurement technology with a compact and user-friendly instrument. With its innovative measuring principle, it doesn't use optical filters.
UV light is spectrally detected and analyzed in the UVpad. Thus, measurements are traceable to national standards. Since it works without a filter, it is particularly suitable for the measurement and comparison of different lamps.
All measurement data are displayed on the device immediately; 50 measurements are stored in the UVpad and can be read via USB. The supplied PC software evaluates the irradiance intensity profiles measured separately for UVA, UVB, UVC, and VIS. Spectrum and measurement data can be exported and saved.
Optionally, UV systems can be optimized due to saved operating functions such as, for example, the absorption spectra of photoinitiators. Thus, the operating costs can be reduced and the product quality can be ensured.
Notes for spectroradiometer and broadband radiometer
Broadband and spectral radiometers are used in UV measurement technology to monitor lamp performance. However, broadband radiometers are calibrated to only one lamp type and differ in their sensitivity to each other. This makes comparisons between the measurements of different manufacturers and comparisons between systems with different lamps (e.g., Hg, Ga, Fe) or UV LEDs impossible. In contrast, by means of spectral radiometers, all UV lamps can be measured.
For example, as doped radiation sources age, the spectrum changes. UV systems and aging of the radiation sources can be conveniently monitored and documented with the UVpad.
This makes the UVpad a handheld spectral UV instrument: it delivers the spectrum without a connected computer and without a light guide, right where the sample sits.
| Product type | Spectroradiometer: Flattest spectral UV radiometer (14.4 mm) for conveyors, LEDs and spot lamps |
| Spectral range | 200–440 nm (spectrally resolved) |
| Measuring range | Irradiance: 2–5000 mW/cm² (standard), 25–35000 mW/cm² (high-power), 1–5000 W/m² (high-sensitivity); Dose: 1 mJ/cm²–600 J/cm² (standard), 25 mJ/cm²–4200 J/cm² (high-power), 0.1 J/m²–5000 J/m² (high-sensitivity) |
| Calibration uncertainty (typ.) | 5.0–9.5 % (k = 2) |
| Output / interface | Interface: USB |
| Time resolution | Data storage rate: 100 Hz–1 Hz, adjustable |
| Calibration | traceable to the PTB; factory calibration, recalibratable |
| Standards / guidelines | no product-specific standard; calibration per DIN EN ISO/IEC 17025:2018 available |
| Suitable for | Additive manufacturing and 3D printing; Plants, agriculture and food; UV curing and photopolymerisation; UV bonding, potting and encapsulation |
| Not suitable for | irradiance above 5000 mW/cm² (standard range); sensor temperatures above 70 °C; use under water or under pressure; VUV measurement at 172 nm |
| Datasheet revision | Rev. 2026-09-08 (e_uvpad_uv_radiometer.pdf) |
The calibration uncertainty stated above is the expanded uncertainty of the calibration (k = 2, confidence level approx. 95 %) and applies to the calibration source and the calibration conditions. In use the measurement uncertainty is larger: spectral mismatch at the source actually used, the sensor temperature, ageing since calibration as well as distance and alignment to the source are added to it. How these combine into an uncertainty budget is explained under Measurement uncertainty in UV measurement.
Highlights of spectral UV radiometer
- Spectral radiometric measurements without a PC
- 200 - 440 nm (total UV spectral range)
- 512 photo diodes
- Battery operated
- Height only 14.4 mm
- USB for data export
- Internal memory for 50 measurements
Experience the UVpad as an interactive 3D model
Rotate the housing, operate the display and try out the menu navigation – just like on the real device.
The UVpad can be viewed from all sides in the 3D product viewer – true to the original, generated from the CAD design data. If you like, switch the display on and click through the menu navigation, just as on the real device.
Technical data UV radiometer UVpad
| Spectral range | 200–440 nm ± 5 nm |
| Versions | standard, high-power, high-sensitivity |
| Spectral bandwidth | 2 nm |
| Irradiance | 2–5000 mW/cm² (standard), 25–35000 mW/cm² (high-power), 1–5000 W/m² (high-sensitivity) |
| Dose | 1 mJ/cm² - 600 J/cm² (standard), 25 mJ/cm² - 4200 J/cm² (high-power), 0.1 J/m² - 5000 J/m² (high-sensitivity) |
| Resolution | 0.1 mW/cm² / 1 mW/cm² |
| Calibration | traceable to the PTB |
| Calibration uncertainty, typical | 5.0–9.5 % |
| Cosine correction | yes |
| Data storage rate | 100 Hz to 1 Hz, adjustable |
| Measuring time | 5 s to 8 min, depending on the data storage rate |
| Sampling rate | 10 ms - 1000 ms |
| Display | graphical, 128 × 64 px |
| Dimensions | 160 × 100 × 14.4 mm |
| Sensor position | back side |
| Weight | about 375 g |
| Permissible operating temperature | 70 °C, briefly up to 60 s at 120 °C ambient temperature |
| Power supply | internal lithium-ion battery |
| Memory | 50 measurements |
| Interface | USB |
| System requirements | Windows 11, 300 MB HDD, 4 GB RAM |
Frequently asked questions: UVpad
The UVpad Standard measures 2–5000 mW/cm², the UVpad High Power 25–35,000 mW/cm² for focused UV LED and spot lamps, the UVpad High Sensitivity 1–5000 W/m² for weak sources. All versions measure spectrally from 200 to 440 nm with 2 nm bandwidth via an array of 512 photodiodes and are designed with 14.4 mm height for conveyor systems; the dose is recorded up to 600 J/cm² (High Power up to 4200 J/cm²).
Because it measures spectrally: the UVpad splits the radiation into wavelengths and only afterwards integrates the irradiance over UVA, UVB, UVC or a custom weighting. A broadband radiometer, in contrast, is matched to a calibration lamp and shows a mismatch of often 5–20 % with a differently distributed spectrum. With the UVpad, medium-pressure lamp and 395 nm LED can therefore be compared directly in the same unit, including peak wavelength.
The typical calibration uncertainty is 5.0–9.5 % (k = 2) and is traceable to the PTB; calibration is performed in Opsytec's accredited laboratory per DIN EN ISO/IEC 17025:2018 as an option. The value depends on the spectral range because the uncertainty of the irradiance standards is larger in the short-wave UVC than in the UVA. Opsytec recommends recalibration every 12 months; the storage of 50 measurements with spectrum enables comparison over time.
The calibration certificate states the expanded calibration uncertainty with k = 2; for the UVpad it is typically 5.0–9.5 %. In use the measurement uncertainty is larger, because spectral mismatch at the source actually used, sensor temperature, ageing and measuring geometry are added to it. How these combine into an uncertainty budget is explained under Measurement uncertainty in UV measurement.
Order numbers, scope of delivery, accessories and versions
| Device | Order number |
|---|---|
| UVpad | 670011 |
Scope of delivery: the UVpad, the factory calibration certificate, a USB cable and a transport case.
| Order number | 670011-P |
|---|---|
| Spectral bandwidth | 2 nm |
| Irradiance | 25–35000 mW/cm² |
| Dose | 25 mJ/cm² - 4200 J/cm² |
| Resolution | 1 mW/cm² |
For UV-LED lamps with the highest power. All other data are those of the standard version.
| Order number | 670011-H |
|---|---|
| Spectral bandwidth | 4 nm |
| Irradiance | 1–5000 W/m² |
| Dose | 0.1 J/m² - 5000 J/m² |
| Resolution | 1 W/m² = 0.1 mW/cm² |
For UV fluorescent lamps, solar simulators and applications with a low irradiance. All other data are those of the standard version.
| Designation | Order number |
|---|---|
| ISO 17025 calibration | 17026-1 |
Accredited ISO 17025 calibration and testing in our own calibration laboratory. On delivery the UVpad is already factory-calibrated; the ISO 17025 calibration can be ordered as an option.
Used in these application fields
The UVpad measures where a sensor has to travel with the part or fit into a flat installation space: in the dose profile of a conveyor line in UV curing, at the joint in UV bonding, potting and encapsulation, in the cap tunnel of filling technology, on components in optics manufacturing and during post-curing in additive manufacturing.
The UVpad measures the spectrum where the sample sits, which is why it appears in work that has to document the spectral distribution. Most recently published:
- Influence of different UV spectra and intensities on yield and quality of cannabis inflorescences — Huebner, D. S.; Batarshin, M.; Beck, S. et al. · Frontiers in Plant Science · 2024
- On-Site Inactivation for Disinfection of Antibiotic-Resistant Bacteria in Hospital Effluent by UV and UV-LED — Azuma, T.; Usui, M.; Hasei, T. et al. · Antibiotics · 2024
- Multiparameter Single Sensor for Space Silicone Adhesive Monitoring Under High-Vacuum Ultraviolet Exposure — Fazzi, L.; Dias, N.; Holynska, M. et al. · Journal of Spacecraft and Rockets · 2023
- Quantification and elucidation of the UV‐light triggered initiation kinetics of TPO and BAPO in liquid acrylate monomer – Ruhland, K.; Habibollahi, F.; Horny, R. · Journal of Applied Polymer Science · 2019
- Diklofenaakin ja diatritsoaatin kvantitatiivisten ja kvalitatiivisten tutkimuksien analyysimenetelmät — 2022
The details come from Crossref. Authorship and content rest with the respective research groups.
These are the rules most often consulted in practice for spectrometers — from measurement through limits to the requirements on the device:
- DIN EN ISO/IEC 17025:2018-03 — General requirements for the competence of testing and calibration laboratories
- DIN EN 62471:2009-03 — Photobiological safety of lamps and lamp systems
- DIN EN 14255-1:2005 — Measurement and assessment of personal exposure to incoherent optical radiation — Part 1: UV radiation from artificial sources in the workplace
All rules for spectrometers are listed in the standards finder.
Not a normative reference. What counts is always the currently valid edition in the original text.
