Vernier UVB-BTA User manual

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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 UVB sensor would not correspond to the readings from the
Vernier UVB 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.
Specifications
UV peak sensitivity one volt per 204 mW/m2at 300 nm
Wavelength sensitivity region,
approximate
265 to 322 nm, 10% sensitivity points.
See graphs for more detail.
12-bit resolution 0.25 mW/m2
Dimensions 21 cm by 2 cm diameter
Time response approximately 2 seconds to reach 95% of
final reading
Stored calibration slope (gain): 204 mW/(m² V)
intercept (offset): 0
Irradiance Vout * 204 mW/(m2V)
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 UVB 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 UVB region.
The signal from the diode is amplified and sent to the output.
UV Terminology
The Vernier UVB and UVA (order code UVA-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.
UVB Sensor
(Order Code UVB-BTA)
The UVB Sensor is an ultraviolet light sensor
that responds primarily to UVB radiation
(approx. 265 to 322 nm). The UVB sensor is
recommended for experiments involving
sunlight.
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
See www.vernier.com/manuals/uvb-bta for a list of software compatible with the
UVB Sensor.
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:
www.vernier.com/start/uvb-bta
Calibrating the Sensor
You do not have to perform a new calibration when using the UVB 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 UVB 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.

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Warranty
Warranty information for this product can be found on the Support tab at
www.vernier.com/uvb-bta
General warranty information can be found at www.vernier.com/warranty
Disposal
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.
Vernier Software & Technology
13979 SW Millikan Way • Beaverton, OR 97005-2886
Toll Free [phone] • [phone] • Fax [phone]
[email protected] • www.vernier.com
Rev. 08/13/21
Logger Pro, Graphical Analysis, Vernier LabQuest, Vernier LabQuest Mini, and other marks shown are our
trademarks or registered trademarks in the United States.
iPad is a trademark of Apple Inc., registered in the U.S. and other countries.
All other marks not owned by us that appear herein are the property of their respective owners, who may or may not
be affiliated with, connected to, or sponsored by us.
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 UVB
sensor therefore cannot report UV index.
Troubleshooting
For troubleshooting and FAQs, see www.vernier.com/til/1442
Repair Information
If you have watched the related product video(s), followed the troubleshooting
steps, and are still having trouble with your UVB Sensor, contact Vernier
Technical Support at [email protected] 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.