UVpad E – precise spectral UV measurements
The UVpad E is a spectroradiometer with an external sensor for measuring UV irradiance, UV dose and spectrum. 512 photodiodes cover the wavelength range from 240 nm to 480 nm ± 5 nm at a spectral bandwidth of 2 nm; the measuring range runs from 2 to 5000 mW/cm², and from 25 to 20,000 mW/cm² in the high-power version. The classification into UVA, UVB and UVC is standard-compliant and traceable.
The UVpad E combines the benefits of the spectral measuring technology with a handheld and easy-to-operate radiometer. The UVpad E is technically based on our successful radiometer UVpad. With the external sensor and an optimized device software, it is even more precise and easier to operate.
Use the spectroradiometer UVpad E for an accurate measurement of the UV irradiance and for comparisons of different UV lamps and UV LEDs. 512 photodiodes measure the spectrum in the wavelength range of 240–480 nm. The classification in UVA, UVB and UVC is performed according to international standards and traceable. The calibration to only one light source is omitted.
During the measurement, the spectrum is shown on the graphic display. The irradiances for UVA, UVB, UVC and VIS are available by the click of a button. In the background, the spectrum is already recorded. While measuring, the dose and the chronological irradiance sequence can additionally be documented. Spectra and measurement data can be exported and evaluated with the provided software. In addition, the UVpad E can be used as a classical PC controlled spectrometer.
The UVpad E is supplied factory-calibrated. Optionally, we offer an accredited calibration and testing to DIN EN ISO/IEC 17025:2018-03.
With our radiometers RM-12, RMD Pro and the spectroradiometer UVpad E, we cover the entire range of the UV measuring technology. We would be pleased to assist you selecting a suitable UV measuring device.
| Product type | Spectroradiometer: Spectroradiometer with external sensor head for UVA, UVB, UVC and hard-to-reach points |
| Spectral range | 240–480 nm (spectrally resolved) |
| Measuring range | 2–5000 mW/cm² (standard), 25–20000 mW/cm² (high-power), 1–1000 mW/cm² (high-sensitivity); Dose: 0.01 mJ/cm²–600 J/cm² |
| Calibration uncertainty (typ.) | 5.0–9.5 % (k = 2) |
| Output / interface | Interface: USB |
| Time resolution | Measuring time: 5 s–8 min, depending on the data storage rate |
| 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 | Photobiology and biotechnology; UV curing and photopolymerisation; Electronics and semiconductors; Pharma and photostability |
| Not suitable for | irradiance above 5000 mW/cm² (standard range); sensor temperatures above 60 °C; use under water or under pressure; VUV measurement at 172 nm |
| Datasheet revision | Rev. 2026-09-08 (e_uvpad-e-spectral-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.
Screenshots UVpad viewer for spectral radiometer UVpad E
Connect the UVpad to the PC in order to indicate, evaluate and save the measurements. Due to the simple comparison of the measurement data, changes in the spectrum, irradiance or dose are possible at the touch of a button. With each measurement, the measurement data and time are saved. With the ability to save comments, you will always maintain an overview, even with various measurements.
Experience the UVpad E as an interactive 3D model
Rotate the housing and the sensor head, operate the display and try out the menu navigation – just like on the real device.
The UVpad E can be viewed from all sides in the 3D product viewer – true to the original, generated from the CAD design data, including the input optics and the light guide. The external sensor on its cable is included as well – the feature that sets the UVpad E apart from the UVpad and gets it into narrow irradiation chambers.
Technical data spectra radiometer UVpad E
| Spectral range | 240–480 nm ± 5 nm |
| Versions | standard, high-power, high-sensitivity |
| Spectral bandwidth | 2 nm |
| Pixel distance | about 0.5 nm |
| Measuring range, typical | 2–5000 mW/cm² (standard), 25–20000 mW/cm² (high-power), 1–1000 mW/cm² (high-sensitivity) |
| Resolution | 0.01 mW |
| Dose | 0.01 mJ/cm² - 600 J/cm² |
| Measuring time | 5 s to 8 min, depending on the data storage rate |
| Memory | 50 measurements |
| Sampling rate | 10 ms - 10 s |
| Data storage rate | 100 Hz to 1 Hz |
| Display | graphical, 128 × 64 px |
| Dimensions | 160 × 100 × 20 mm |
| Weight | about 500 g |
| Sensor dimensions, type 1 | Ø 40 mm, h 35 mm |
| Sensor dimensions, type 2 | Ø 40 mm, h 25 mm |
| Sensor dimensions, type 3 | Ø 40 mm, h 10 mm |
| Optical fibre, length | 1.5 m |
| Optical fibre, type | UV silica fibre with metal shielding |
| Optical fibre, connector | SMA |
| Sensor weight | about 120 g |
| Sensor, operating temperature | 0 to 70 °C |
| Sensor, humidity | below 80 %, non-condensing |
| Permissible operating temperature | 0 to 60 °C |
| Storage temperature | -10 to 60 °C |
| Humidity | below 80 %, non-condensing |
| Power supply | internal lithium-ion battery |
| Interface | USB |
| System requirements | Windows 10 or 11, 300 MB HDD, 1 GB RAM |
| Calibration | traceable to the PTB |
| Cosine correction | yes |
Frequently asked questions: UVpad E
The UVpad E carries the radiation via an external sensor head with SMA light guide to the spectrometer, whereas the UVpad has the sensor in its flat housing. The UVpad E therefore measures at points where no 14 mm device fits, for example inside an irradiation chamber, at a reactor window or at hot lamps, while the electronics stay outside. The spectral range is 240–480 nm at 2–5000 mW/cm² (High Power up to 20 W/cm²).
Yes. The ICH guideline Q1B requires proof of at least 200 Wh/m² UVA exposure and 1.2 million lux hours of visible light. The UVpad E measures the UVA irradiance spectrally with its range from 240 to 480 nm and calculates the dose over the chamber runtime; the sensor head lies on the sample plane. For the lux hours a LUX sensor on the RMD is added or the SR900 with a range up to 1100 nm is used.
The standard version measures 2–5000 mW/cm², the High Power version 25–20,000 mW/cm²; the dose is recorded up to 600 J/cm². Since the head contains only the optics, it tolerates higher temperatures than the instrument; the sensor head is rated for 0 to 70 °C, the instrument for 0 to 60 °C. For UV LED lamps in the focus the High Power version is intended to avoid saturation of the 512-pixel array.
The calibration certificate states the expanded calibration uncertainty with k = 2; for the UVpad E 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 E | 670027 |
Scope of delivery: the UVpad E, an optical fibre of 1.5 m, the external sensor type 1 (unless stated otherwise), the factory calibration certificate, the software, a USB cable and a transport case.
| Order number | 670027HP |
|---|---|
| Measuring range | 25–20000 mW/cm² |
For UV lamps with a high irradiance. All other data are those of the standard version.
| Order number | 670027HS |
|---|---|
| Measuring range | 1–1000 mW/cm² |
For 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 E is already factory-calibrated; the ISO 17025 calibration can be ordered as an option.
| Sensor head | Dimensions |
|---|---|
| Type 1 | Ø 40 mm, h 35 mm |
| Type 2 | Ø 40 mm, h 25 mm |
| Type 3 | Ø 40 mm, h 10 mm |
The sensor head is stated with the order. Without a statement we supply type 1. All three types are connected through the optical fibre (1.5 m).
