• CO₂ Gas Sensor
• 250 mL gas sampling bottle (Nalgene bottle with lid)

Choose a platform below to see its compatibility requirements. This sensor requires an interface (sold separately).

LabQuest

Interface	LabQuest App
LabQuest 3	Full support
LabQuest 2 (discontinued)	Full support
LabQuest (discontinued)	Full support

Computers

	Software
Interface	Graphical Analysis	Logger Pro	Logger Lite
LabQuest Mini	Full support	Full support	Full support
LabQuest 3	Full support	Full support	Incompatible
LabQuest 2 (discontinued)	Full support	Full support	Full support
LabQuest Stream (discontinued)	Full support 1	Full support	Full support 1
Go!Link	Full support	Full support	Full support
LabQuest (discontinued)	Full support	Full support	Full support
LabPro (discontinued)	Incompatible	Full support	Full support

Compatibility Notes

1. Connect LabQuest Stream via USB. Wireless connection is not supported.

Chromebook

	Software
Interface	Graphical Analysis
LabQuest Mini	Full support
LabQuest 3	Full support
LabQuest 2 (discontinued)	Full support
LabQuest Stream (discontinued)	Full support 1
Go!Link	Full support
LabQuest (discontinued)	Full support

Compatibility Notes

1. Connect LabQuest Stream via USB. Wireless connection is not supported.

iOS

	Software
Interface	Graphical Analysis	Graphical Analysis GW
LabQuest Stream (discontinued)	Full support	Full support
LabQuest 3	Full support 1	Full support 1
LabQuest 2 (discontinued)	Full support 1	Full support 1

Compatibility Notes

1. iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.

Android

	Software
Interface	Graphical Analysis	Graphical Analysis GW
LabQuest Stream (discontinued)	Full support	Full support
LabQuest 3	Full support 1	Full support 1
LabQuest 2 (discontinued)	Full support 1	Full support 1

Compatibility Notes

1. iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.

Arduino

	Software
Interface	Arduino
Vernier Arduino® Interface Shield	Full support

LabVIEW

	Software
Interface	NI LabVIEW
SensorDAQ (discontinued)	Full support
Vernier myDAQ Adapter	Full support 1
Go!Link	Full support
LabQuest Mini	Full support
LabQuest Stream (discontinued)	Full support
LabQuest 3	Full 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

	Software
Interface	EasyData	DataMate	TI-84 SmartView	DataQuest	TI-Nspire Software
EasyLink	Full support 1	Incompatible	Full support 2	Full support	Full support 2
CBL 2 (discontinued)	Full support 3	Full support 3 4	Incompatible	Incompatible	Incompatible
LabPro (discontinued)	Full support 3	Full support 3 4	Incompatible	Incompatible	Incompatible
TI-Nspire Lab Cradle (discontinued)	Incompatible	Incompatible	Incompatible	Full support	Full 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.

1. Plug the sensor into the interface (LabQuest 3, LabQuest Mini, etc.).
2. Connect the interface to your device.
   • If using USB, connect to the USB port on your computer.
   • If using Bluetooth^® wireless technology, click your interface type and then select your device.
3. Prepare for data collection:
   • Vernier Graphical Analysis^®: Launch the app, if necessary, and click Sensor Data Collection.
   • LabQuest^® App: Choose New from the File menu.

The software will identify the sensor and load a default data-collection setup. You are now ready to collect data.

Need Additional Information?

Visit the following link:

www.vernier.com/start-lq-sensor

1. Set the range switch on the sensor.

2. Connect the sensor following the steps in the Quick Start section of this user manual.

The following includes additional important information about the CO₂ Gas Sensor.

• Allow the CO₂ Gas Sensor to warm up for about 90 seconds before collecting data. During warmup, the readings may be very low.
• The CO₂ Gas Sensor is sensitive to high humidity. Do not use it in a condensing environment.
• Most experiments will use the Low range (0–10,000 ppm). The High range would be appropriate when measuring human respiration as expired air is typically 40,000–60,000 ppm CO₂.
• The CO₂ Gas Sensor is somewhat sensitive to temperature changes. In most cases, variations in CO₂ readings due to temperature changes are small (<100 ppm on Low range, <1000 ppm on High range). The sensor is designed to operate between 20 and 30°C. It can be used outside of this temperature range; however, the readings will be less accurate, even if you calibrate the sensor at the lower or higher temperature. With good experimental design, the variation in CO₂ readings due to a temperature change will be negligible compared to the overall change in CO₂ concentration. If an entire experiment is to be conducted at a constant temperature, you could improve the accuracy of the readings by calibrating the sensor at that temperature. Allow enough time for your CO₂ Gas Sensor to stabilize at the desired operating temperatures.
• The CO₂ Gas Sensor has a default sampling rate of 1 sample every 4 seconds. Faster sampling rates are not recommended. Gas must diffuse through the holes in the sensor tube before the sensor detects any changes in concentration. Because diffusion of gases is a slow process, there can be delays in the readings.
• To collect data in a controlled environment, it is recommended that you use the 250 mL gas sampling bottle that is included with your sensor.
• To collect data simultaneously with the CO₂ Gas Sensor and O₂ Gas Sensor, it is recommended that you purchase either the BioChamber 250 (250 mL capacity) or the BioChamber 2000 (2 L capacity). Each BioChamber has a second opening with a grommet so that you can insert two probes at once.
• Because the sensor operates using IR radiation, you should avoid placing the sensor in direct sunlight as much as possible during experiments. Even though the IR detector is shielded, it is best to avoid the possibility of reflected light affecting the readings by keeping the sensor in the shade when used outdoors.
• Best results are obtained when only one CO₂ Gas Sensor is connected to an interface at a time. The current draw from two or more CO₂ Gas Sensors connected to the same interface can cause erroneous data.

You should not have to perform a new calibration very often when using the CO₂ Gas Sensor. A calibration is stored on the sensor before it is shipped. If you do find that you need to calibrate your CO₂ Gas Sensor, it can be done using a sample of outside air, which typically has a CO₂ gas concentration of about 400 ppm. Levels in your area may be slightly higher due to localized influences such as automobile or industrial emissions of carbon dioxide. Note: This calibration method is different from the usual two-point calibration performed with other Vernier sensors. To calibrate the CO₂ Gas Sensor:

1. Fill the gas sampling bottle (included with the sensor) to the brim with water, take it outside, and dump the water to ensure it is filled with fresh air. While still outdoors, insert the sensor into the gas sampling bottle containing fresh outside air. You can now take the bottle and sensor to the location where the calibration is to be done.
2. Connect the CO₂ Gas Sensor to the data-collection interface. Start the data‑collection software and identify your interface, if necessary. Let the sensor warm up for at least 90 seconds.
3. When the CO₂ Gas Sensor has warmed up (readings should have stabilized), use a paper clip to press down the calibration button. Release the button as soon as the red light starts to blink. After about 30 seconds, the reading should stabilize at a value of approximately 400 ppm ±100 ppm in low range (or 400 ppm ±200 ppm in high range). If the reading is significantly lower or higher than 400 ppm, simply press the button again to repeat the process. Note: If the red light stays on solid, you have held the button too long. In this case, wait for it to go off and press it again, releasing as soon as it begins to flash.

Measurement range of CO2 Gas Sensor	Low range: 0 to 10,000 ppm CO2 High range: 0 to 100,000 ppm CO2
Low range typical accuracy (at standard pressure, 1 atm)	0 to 1,000 ppm ±100 ppm 1,000 to 10,000 ppm ±10% of reading
High range typical accuracy	0 to 100,000 ppm ±20% of reading
Response time	95% of full-scale reading in 120 seconds
Warm-up time	90 seconds
Pressure effect	0.19% of reading/mm of Hg from standard pressure
Output signal range	0 to 4.0 V
Input potential	5 V (±0.25 V)
Gas sampling mode	diffusion
Normal operating temperature range	25°C (±5°C)
Operating humidity range	5 to 95% (non-condensing)
Storage temperature range	–40 to 65°C

*For units purchased prior to 2007, see www.vernier.com/til/3730

Very important: Do not expose the CO₂ Gas Sensor to any liquids, including water. The sensor is intended only for measuring gaseous, not aqueous, CO₂ concentration.

Temperatures greater than 65°C will damage the sensor.

It is recommended that you wash the gas sampling bottles by hand. Most dishwashers will melt the plastic.

The Vernier CO₂ Gas Sensor measures gaseous carbon dioxide levels in the range of 0 to 10,000 ppm (Low range setting) or 0 to 100,000 ppm (High range setting) by monitoring the amount of infrared radiation absorbed by carbon dioxide 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.

• If the reported CO₂ 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 CO₂ 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 CO₂.
• If the sensor is reading at or near the maximum value for the set range, the CO₂ 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 CO₂ 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

If you have watched the related product video(s), followed the troubleshooting steps, and are still having trouble with your CO₂ Gas Sensor, contact Vernier Technical Support at support@vernier.com 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.

Item	Order Code
BioChamber 250	BC-250
BioChamber 2000	BC-2000
250 mL Nalgene Bottle w/Lid	CO2-BTL