UV irradiance sensor


The SolarSIM-UV brings our SolarSIM technology to bear on the challenge of solar UV measurement. The result is a UV sensor like no other.

The SolarSIM-UV uses multi-spectral measurement to accurately resolve the solar spectral irradiance over the full UV range. From this, all the UV components are then precisely extracted.

Measurands: UV-Total, UV-A, UV-B, UV-E, UV index, PAR, GHI
Technology: Software-augmented multi-filter radiometer.
Highlights: All UV components from a single sensor. UV spectral and total irradiances.

The only UV sensor you'll ever need.

Measuring solar UV irradiance is tough. The SolarSIM-UV rises to the challenge through the use of multi-spectral measurement. The result is a robust, accurate UV sensor unlike anything else.

The SolarSIM-UV uses filtered photodiodes to make precise, multi-spectral measurements of the solar spectrum in several narrow wavelength bands. These measurements then inform Spectrafy’s proprietary algorithms to accurately resolve the global solar spectrum within the UV range.

The SolarSIM-UV software then automatically integrates and processes the UV spectral irradiance to provide the full suite of UV parameters, including UV-T, UV-A, UV-B, UV-E and UV index. Because the UV components are obtained directly from spectral integrals, the limitations associated with traditional UV sensors , such as imperfect filter profiles and spectral selectivity are eliminated.

This innovative approach makes the SolarSIM-UV the first, and only sensor capable of resolving all UV components at the same time, thereby greatly simplifying the sensor count required for comprehensive UV monitoring.

Applications for the SolarSIM-UV include weather forecasting, VU reporting for public health, ground truthing of climate models, agricultural monitoring and material testing.

The SolarSIM-G can generate up to 20 high-quality data streams. Choose what you need:

Global UV spectral irradiance Solar spectral irradiance over the 280-400nm wavelength range, with 1nm resolution.
UV-A Solar global irradiance within the wavelength range of 315 - 400nm.
UV-B Solar global irradiance within the wavelength range of 280 - 315nm.
UV-T Solar global irradiance within the wavelength range of 280 - 400nm.
UV-E UV irradiance weighted to the response of human skin, per IEC 17166.
UV-Index Based on UV-E, the international scale the quantifies the potential for UV irradiance to damage human skin.
Photosynthetically active radiation Total irradiance within the 400-700nm wavelength range.
Meteorological parameters Ambient temperature, relative humidity and atmospheric pressure.

The SolarSIM-UV comes with powerful software to process and visualize your data.

The SolarSIM-UV comes with powerful software to process and visualize its data
The SolarSIM-UV software sits-offboard the sensor and processes the raw irradiance measurements to generate the various data streams. A Windows-based GUI provides the user with easy visualization of the SolarSIM-UV’s data streams. A command line version of the software is also available for network and datalogger-based applications.

Multiple options for maximum ease.


With RS-485 ASCII digital output, the SolarSIM-UV can connect to any RS-485 capable datalogger. Sample datalogger code is available upon request.


Get your SolarSIM-UV working straight out of the box with our custom power/comms converter. The Combox allows you to connect to and power a SolarSIM-UV directly through a laptop or PC.

Serial over ethernet

The SolarSIM-UV can be connected to a networked PC/server via a suitable SoE device. Hardware recommendations are available upon request.


UV-Total 280 – 400 nm
UV-A 315 - 400 nm
UV-B 280 - 315 nm
UV-E per IE17166
PAR 400 - 700 nm
GHI 280 - 4000 nm
Spectral response n/a - measurements integrated from spectra
Response time (95%) < 0.5 s
Cosine response ±3% at 80º zenith
Non-stability (change/year) < 1.0 %
Non-linearity < 0.5 %
Temperature response < 0.1% (in-situ temperature correction)
Calibration uncertainty 1.1%
Exposure time < 1 ms
Max acquisition rate 0.5 Hz

Spectral Irradiance

Spectral range 280-400 nm
Spectral resolution (FWHM) 1 nm
Wavelength Accuracy ± 0.1nm
Spectral measurement uncertainty < 5% per wavelength
Exposure time < 1ms
Max acquisition rate 0.5 Hz
Temperature dependency < 0.1% (on-board temp. correction)


Weight 1.2 kg
Dimensions 132 x 132 x 110 mm
Power supply and use 12 VDC, <1W
Communication RS-485 ASCII, Direct to PC, serial over ethernet, datalogger
Operating temperature range -30 to 65 °C
Humidity Range 0 to 100% RH

The only UV sensor you'll ever need.

Public health UV irradiance can significantly damage human skin, resulting in sun burn, premature ageing and even some forms of cancer. Widespread deployment of UV sensors help the public understand local UV conditions in real-time.
Agricultural monitoring Ultraviolet light is known to have adverse effects on plants and animals. UV measurement networks allow industry an researchers to quantify and predict the effects of naturally occurring UV light on our food chains.
UV load monitoring for material testing Accurately quantifying the UV exposure of new materials and coatings during outdoor testing provides important insights into their real world performance.

How does the SolarSIM-UV work?

The SolarSIM-UV is a software augmented multi-filter radiometer. It uses filtered photodiodes to make precise, multi-spectral measurements of the solar spectrum in several narrow wavelength bands. These measurements then inform the SolarSIM-UV’s software to accurately resolve the complete global solar spectrum, under all sky conditions. From this detailed spectral irradiance, the SolarSIM-UV's software then automatically calculates the relevant UV components.

Why would I choose a SolarSIM-G over another UV sensor?

The SolarSIM-UV is the only UV sensor that resolves UV irradiance directly from spectral irradiance. This eliminates the spectral errors often inherent in other UV sensors, i.e. when the spectral response of the sensors does not exactly match the wavelength range of the desired UV measurand. In addition, the SolarSIM-UV's spectral measurement approach means that it is the only sensor capable of measuring all UV components at once, greatly reducing the capital and ongoing maintenance cost of comprehensive UV measurement.

What does the SolarSIM-UV software do?

The core of the SolarSIM-UV software is a proprietary radiative transfer model that uses the SolarSIM-UV's multi-spectral measurements of sunlight, along with its measurements of ambient temperature, pressure and humidity to reconstruct the global solar spectral irradiance over the 280-4000nm range. From this detailed spectral irradiance, the software then automatically calculates the relevant UV components. It is available as a GUI and as a command-line executable.

Does Spectrafy sell complete measurement systems?

Yes, we can provide you with a complete turn-key system so you can hit the ground running with your SolarSIM-UV measurements.

How do I connect a SolarSIM-UV to my datalogger?

The SolarSIM-UV communicates via RS-485 ASCII. As such it can connect to any datalogger that accepts RS-485 or RS-232 inputs. Sections 4 and 6 of the SolarSIM-UV User Manual provides details regarding data logger integration, as do our data logger app notes found in the SolarSIM-UV download section.

How is the SolarSIM-UV calibrated?

All SolarSIM-UV production units undergo electrical, thermal and optical calibration. The optical calibration is performed on-sun against our SolarSIM-UV reference sensors The reference sensors are calibrated for absolute irradiance at NREL in Golden Colorado and are traceable to NIST Spectral Irradiance Standard Model FEL lamps.

How often should I get my SolarSIM-UV recalibrated?

We recommend recalibration every year in order to ensure the highest measurement accuracy. Recalibration is performed on-sun, at Spectrafy HQ in Ottawa, Canada. Please contact us prior to shipping your unit in order to ensure the swiftest calibration process possible.

How does the process of upgrading my SolarSIM-UV to add additional measurement functions work?

The SolarSIM-UV can be purchased with any or all of its measurement capabilities activated. Additional measurement options can be added at any point in the future via a simple software upgrade. At the same time, users can also choose to have their historical data reprocessed, to include the new measurand(s) from inception.



The Combox is a power and comms converter that allows the user to connect to and power their SolarSIM directly through a PC or laptop.
MP-G Mounting Plate

MP-G Mounting Plate

We offer a range of standard, anodized aluminum mounting plates suitable for mounting the SolarSIM-G series sensors. Custom options are also available.
GV-1 Ventilator

GV-1 Ventilator

The GV-1 ventilator maximizes the reliability and accuracy of SolarSIM-G, SolarSIM-GPV, SolarSIM-UV and SolarSIM-ALB measurements while minimizing maintenance, by reducing the effects of dust, raindrops and dew.
SolarSIM-E Automated shadowband

SolarSIM-E Automated shadowband

The SolarSIM-E leverages the SolarSIM-G to enable accurate and affordable measurements of full range spectra and broadband irradiance for all three irradiance components (global, diffuse and direct).
TMP-G Tripod Mounting Platform

TMP-G Tripod Mounting Platform

Our tripod mounting platform with integrated mounting plate, provides a rugged, easily installed solution for deploying your SolarSIM-G, SolarSIM-GPV or SolarSIM-UV sensor in the field.
ST-5 Sun Tracker

ST-5 Sun Tracker

The optimum combination of performance, reliability and cost. Combine with the SolarSIM-D2. Combine with the SolarSIM-G, SolarSIM-GPV or SolarSIM-UV for direct global or single-axis tracked plane-of-array irradiance measurements.
CC-G Carry Case

CC-G Carry Case

Hard plastic, waterproof, shockproof and dust proof carry case with custom foam cut outs to keep your SolarSIM-G/GPV/UV/GE safe and snug.
Data loggers

Data loggers

Spectrafy offers a range of third-party dataloggers preconfigured with the data logger code required to interact with the SolarSIM sensors.