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UVA Sensor User Manual

Order Code: UVA-BTA

The UVA Sensor is an ultraviolet light sensor that responds primarily to UVA radiation (approx. 320 to 390 nm). The UVA sensor is recommended for experiments that use a UV lamp.

Note: Vernier products are designed for educational use. Our products are not designed nor are they recommended for any industrial, medical, or commercial process such as life support, patient diagnosis, control of a manufacturing process, or industrial testing of any kind.

Compatible Software

Choose a platform below to see its compatibility requirements.

InterfaceLabQuest App
LabQuest 3Full support
LabQuest 2 (discontinued)Full support
LabQuest (discontinued)Full support
InterfaceGraphical AnalysisLogger ProLogger Lite
LabQuest MiniFull supportFull supportFull support
LabQuest 3Full supportFull supportIncompatible
LabQuest 2 (discontinued)Full supportFull supportFull support
LabQuest Stream (discontinued)Full support 1Full supportFull support 1
Go!LinkFull supportFull supportFull support
LabQuest (discontinued)Full supportFull supportFull support
LabPro (discontinued)IncompatibleFull supportFull support

Compatibility Notes

  1. Connect LabQuest Stream via USB. Wireless connection is not supported.
InterfaceGraphical Analysis
LabQuest MiniFull support
LabQuest 3Full support
LabQuest 2 (discontinued)Full support
LabQuest Stream (discontinued)Full support 1
Go!LinkFull support
LabQuest (discontinued)Full support

Compatibility Notes

  1. Connect LabQuest Stream via USB. Wireless connection is not supported.
InterfaceGraphical AnalysisGraphical Analysis GW
LabQuest Stream (discontinued)Full supportFull support
LabQuest 3Full support 1Full support 1
LabQuest 2 (discontinued)Full support 1Full support 1

Compatibility Notes

  1. iOS and Android devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
InterfaceGraphical AnalysisGraphical Analysis GWGoogle Science Journal
LabQuest Stream (discontinued)Full supportFull supportIncompatible
LabQuest 3Full support 1Full support 1Incompatible
LabQuest 2 (discontinued)Full support 1Full support 1Incompatible

Compatibility Notes

  1. iOS and Android devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
Vernier Arduino® Interface ShieldFull support
InterfaceNI LabVIEW
SensorDAQ (discontinued)Full support
Vernier myDAQ AdapterFull support 1
Go!LinkFull support
LabQuest MiniFull support
LabQuest Stream (discontinued)Full support
LabQuest 3Full support
LabQuest 2 (discontinued)Full support
LabQuest (discontinued)Full support

Compatibility Notes

  1. You can only read the raw count/raw voltage output by this sensor. You must do the programming to convert to proper sensor units.
Texas Instruments
InterfaceEasyDataDataMateTI-84 SmartViewDataQuestTI-Nspire Software
EasyLinkFull support 1IncompatibleFull support 2Full supportFull support 2
CBL 2 (discontinued)Full support 3Full support 3 4IncompatibleIncompatibleIncompatible
LabPro (discontinued)Full support 3Full support 3 4IncompatibleIncompatibleIncompatible
TI-Nspire Lab Cradle (discontinued)IncompatibleIncompatibleIncompatibleFull supportFull support

Compatibility Notes

  1. Use with TI-84 Plus calculators only.
  2. Requires an Easy to Go! adapter
  3. CBL 2 and LabPro interfaces cannot be used with TI-84 Plus CE calculators.
  4. DataMate cannot be used with color screen TI-84 Plus calculators; use EasyData with these calculators.

Getting Started

  1. Connect the sensor to the interface (LabQuest Mini, LabQuest 3, etc.).
  2. Start the appropriate data-collection software (Logger Pro®, LabQuest® App, or Graphical Analysis™) if not already running, and choose New from File menu. The software will identify the sensor and load a default data-collection setup. You are now ready to collect data.

If you are collecting data using a Chromebook™, mobile device such as iPad® or Android™ tablet, or a Vernier wireless sensor or interface, please see the following link for up-to-date connection information:

Calibrating the Sensor

You do not have to perform a new calibration when using the UVA sensor. You can use the calibration that is stored on the sensor itself.

It is quite difficult to calibrate a UV sensor to read in absolute units, since you must have a source of known UV intensity and spectral distribution. More often you will simply want to calibrate the sensor in terms of a relative intensity. In that case, you will point the sensor at a UV source (most often the sun) and define that intensity as 100%. To perform this kind of calibration, complete the following steps for a two-point calibration. One of the points is your zero, with no light striking the sensor. Cover the tip of the UVA sensor with a clean opaque object. Select the calibration option of the program you are using. Enter 0 (zero) as the first known intensity. Now allow full UV intensity to strike the sensor. Since the orientation of the sensor affects the reading, it is best to hold the sensor in place with a clamp on a ring stand. To point the sensor directly at the sun, make the shadow of the sensor tube as small as possible. Enter 100 as the next known intensity. Subsequent measurements will be relative to this second intensity.

Note that you cannot calibrate a light sensor using a broadband light source (such as a lamp or the sun) against another light sensor of known calibration unless the spectral response of the two sensors is exactly the same. Similarly, any intensity measurements of a broadband source using two sensors with different spectral response cannot be directly compared. For example, a reading from another manufacturer’s UVA sensor would not correspond to the readings from the Vernier UVA Sensor. In all these cases a direct comparison is not appropriate, since the reading from any light sensor is a convolution of the spectral distribution of the incident light and the spectral response of the sensor.


UV peak sensitivity

one volt per 3940 mW/m² at 340 nm

Wavelength sensitivity region, approximate

320 to 390 nm (320 to 375 nm, half‑sensitivity points)
See graphs for more detail.

12-bit resolution

5 mW/m²


21 cm by 2 cm diameter

Time response

approximately 2 seconds to reach 95% of final reading

Stored calibration

slope (gain): 3940 mW/(m² V)

intercept (offset): 0


Vout * 3940 mW/(m² V)

Care and Maintenance

Do not wrap the cable tightly around the sensor for storage. Repeatedly doing so can irreparably damage the wires and is not covered under warranty.

How the Sensor Works

The Vernier UVA Sensor is built around a broadband UV sensitive silicon photodiode. The diode produces a current proportional to the UV intensity. A wavelength selective filter limits light striking the diode to only the UVA region. The signal from the diode is amplified and sent to the output.

UV Terminology

The Vernier UVA and UVB (order code UVB-BTA) Sensors respond to specific regions of the electromagnetic spectrum. The wavelength region from 320 to 400 nm is commonly called UVA radiation, and 280 to 320 nm is called UVB radiation. Wavelengths shorter than 280 nm fall into the UVC spectrum. Neither Vernier sensor is sensitive to UVC radiation.

Plants and animals respond differently to the three types of UV radiation. Although very harmful to plants and animals, UVC radiation is nearly completely absorbed by the ozone in the Earth’s atmosphere. Some UVB radiation makes it through the atmosphere, although the degree of absorption depends critically on the angle of the sun and the amount of ozone along the light path. UVB radiation is thought to be responsible for reddening of the skin (erythema), cataracts, and skin cancers. UVA can also cause these effects on human skin, but to a lesser extent. It is generally agreed that UVB radiation is the primary danger to humans, but increasingly UVA is being shown to cause delayed, but significant, damage to skin and eyes. The standard erythemal (or sunburning) action spectrum (McKinlay and Diffey, 1987) represents a combined estimate of the relative sensitivity of skin as a function of wavelength. Since knowledge of how UV light affects skin improves with time, the erythemal spectrum may not represent the latest thinking of UV danger.

There are several ways of measuring UV light intensity and exposure. The usual irradiance unit of measurement is mW/cm², but a simplified UV Index system is also in use. The UV Index is actually a forecast, not a measurement. For comparison with the forecast, some UV sensors can be calibrated in terms of UV Index. However, since the UV Index includes a wavelength weighting corresponding to the erythemal action spectrum, only sensors matching the erythemal spectrum can logically be calibrated in terms of UV Index. The UVA sensor therefore cannot report UV index.


For troubleshooting and FAQs, see

Repair Information

If you have watched the related product video(s), followed the troubleshooting steps, and are still having trouble with your Product Name, contact Vernier Technical Support at or call 888-837-6437. Support specialists will work with you to determine if the unit needs to be sent in for repair. At that time, a Return Merchandise Authorization (RMA) number will be issued and instructions will be communicated on how to return the unit for repair.


Warranty information for this product can be found on the Support tab at

General warranty information can be found at


When disposing of this electronic product, do not treat it as household waste. Its disposal is subject to regulations that vary by country and region. This item should be given to an applicable collection point for the recycling of electrical and electronic equipment. By ensuring that this product is disposed of correctly, you help prevent potential negative consequences on human health or on the environment. The recycling of materials will help to conserve natural resources. For more detailed information about recycling this product, contact your local city office or your disposal service.

Contact Support

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