molecules. Carbon dioxide gas moves in and out of the sensor tube by diffusion
through the twenty vent holes in the sensor tube. The sensor uses a small
incandescent light bulb to generate infrared radiation (IR). The IR source is located
at one end of the sensor’s shaft. At the other end of the shaft is an infrared sensor
that measures how much radiation gets through the sample without being absorbed
by the carbon dioxide molecules. The detector measures infrared radiation in the
narrow band centered at 4260 nm. The greater the concentration of the absorbing
gas in the sampling tube, the less radiation will make it from the source through
the sensor tube to the IR detector. The detector produces a voltage that is
converted to ppm (parts per million) by the software.
Troubleshooting
If the reported CO
2
gas concentration appears to be incorrect (after the
90 second warm up), calibrate the sensor as described in the Calibration
section. Keep in mind that indoor CO
2
gas concentration can vary a great deal
and that there will be unit to unit variability of up to a few hundred parts per
million CO
2
.
If the sensor is reading at or near the maximum value for the set range, the CO
2
concentration may be exceeding the maximum value for the setting. Place the
sensor back into outside air or ambient room air and wait for the readings to
decrease.
If there is no change in CO
2
gas concentration during an experiment when one
is expected, it may be your experiment and not the sensor. Test the sensor by
removing it from the reaction chamber and gently blowing on the shaft to see
if it responds to your exhalation.
For more troubleshooting and FAQs, see
www.vernier.com/til/1366
Repair Information
If you have watched the related product video(s), followed the troubleshooting
steps, and are still having trouble with your CO
2
Gas 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.
Accessories/Replacement Parts
Item
Order Code
BioChamber 250
BC-250
BioChamber 2000
BC-2000
250 mL Nalgene Bottle w/Lid
CO2-BTL
Warranty
Vernier warrants this sensor to be free from defects in materials and workmanship
for a period of five years from the date of shipment to the customer (bottle and lid
are excluded). This warranty does not cover damage to the product caused by
abuse or improper use. This warranty covers educational institutions only.
5
Vernier Software & Technology
13979 SW Millikan Way • Beaverton, OR 97005-2886
Toll Free (888) 837-6437 • (503) 277-2299 • FAX (503) 277-2440
[email protected] • www.vernier.com
Rev. 2/8/16
Logger
Pro,
Logger Lite, Vernier LabQuest 2, LabQuest Mini, and other marks shown are our trademarks or
registered trademarks in the United States.
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.
6
