• O₂ 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	Partial support 1
LabQuest 3	Full support 2	Full support 2
LabQuest 2 (discontinued)	Full support 2	Full support 2

Compatibility Notes

1. Data can be collected using the sensor’s default calibration only.
2. 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

Connect the sensor following the steps in the Quick Start section of this user manual. Note: For best results, keep the sensor upright as much as possible during use. Reading may drift if used in a horizontal position.

For many measurements, it will not be necessary to calibrate the O₂ Gas Sensor. The sensor is shipped with a stored calibration. However, this calibration will drift over time, so periodic calibration is recommended.

A two-point calibration can be done following the procedure below.

1. Connect the sensor to your device following the instructions in the Getting Started section.
2. Open the Calibration menu and choose Calibrate Now.
3. Hold the sensor upright. Using a pointed object, such as a straightened paper clip, push and hold the zero button. The button is located on the side of the sensor next to CAL. The voltage should be less than 0.4 V when the button is depressed.
4. Enter a value of 0% for this reading. Select Keep.
5. Release the zero button.
6. Take a second reading. Keep the sensor upright and expose it to open air. The voltage should be 1.8 V or greater. If less than 1.8 V, see the Care and Maintenance section of this user manual.
7. Enter a value of 20.9% oxygen or a corrected value from the table in the Effect of Humidity section of this user manual. Select Keep.
8. Once finished, the sensor should now read 20.9% (or the value entered from the table).
9. Save the calibration to the sensor following the steps for the software you are using. For detailed instructions on calibration see the related links below.
   • For instructions on calibration using Logger Pro computer software, see www.vernier.com/til/2341
   • For instructions on calibration using LabQuest App, see www.vernier.com/til/3394
   • For instructions on calibration using Graphical Analysis, see www.vernier.com/til/3631
   • For instructions on calibration using Graphical Analysis with an iOS or Android device, see www.vernier.com/til/3630

Effect of Humidity

Because the oxygen concentration varies with the amount of water vapor in the atmosphere, you may want to adjust your atmospheric oxygen calibration value to improve accuracy when using the O₂ Gas Sensor. The accepted value of 20.9% for atmospheric oxygen levels is calculated in dry air (0% humidity). If you know the relative humidity of the location at which you are calibrating, you can substitute one of the values below in place of 20.9%.

Relative humidity	0%	25%	50%	75%	100%
Oxygen in % by volume	20.9	20.7	20.5	20.3	20.1

Range	0–27% (0–270 ppt)
Accuracy	± 1% volume O2 (at 760 mmHg)
Resolution	0.01%
Warm up time	< 5 seconds
Response time	90% of final reading in ~12 seconds
Output signal range	0.3 to 5 VDC; 2.7 to 3.8 VDC @ 21% O2
Output impedance	1 KΩ
Input voltage	5 VDC +/–0.25 VDC
Gas sampling mode	Diffusion
Normal operating temperature range	20 to 30°C
Storage temperature range	–20 to +60°C
Pressure range	0.5 to 1.5 atm
Pressure effect	Directly proportional Vout = Vout (standard) × (P/1013)
Default calibration values	slope: 6.6524 %/V intercept: –2.05%
Dimensions	Sensor tube: 45 mm length, 28 mm OD Total length: 135 mm

Important: The O₂ Gas Sensor must be stored upright when not in use. This is necessary to maintain the sensor. Failure to store upright will shorten the life of the sensor.

As your O₂ Gas Sensor ages, the readings will decrease. This is normal, as the chemicals in the electrochemical cell are depleted. It does not mean the sensor is no longer functional; rather, it simply requires that you perform a calibration and store it as described previously. Once the readings in air are below 12% prior to calibration, or 1.8 volts during calibration, the sensor should be replaced. You may choose to have your sensor refurbished and a new element installed, or you may purchase a new sensor.

For tips on how to extend the life of the O₂ Gas Sensor, see www.vernier.com/til/2588

The Vernier O₂ Gas Sensor measures the oxygen concentration in the range of 0 to 27% using an electrochemical cell. The cell contains a lead anode and a gold cathode immersed in an electrolyte. Oxygen molecules entering the cell are electrochemically reduced at the gold cathode. This electrochemical reaction generates a current that is proportional to the oxygen concentration between the electrodes. The sensor output is a conditioned voltage proportional to the reaction current.

• Even though the sensor responds rather quickly to changes in O₂ concentration, the gas has to diffuse into the electrochemical cell located at the top of the sensor shaft before any changes in concentration can be detected. Because the diffusion of a gas is a slow process, there can be some delay in readings.
• To collect data in a controlled environment, we recommend that you use the 250 mL Nalgene collection bottle that is included with your sensor. Place the tip of the sensor into the opening of the bottle and push the sensor into the bottle. When the sensor will go no further, you have a seal. Very important: Do not place the sensor into any liquid. The sensor is intended only for measuring gaseous, not aqueous, O₂ concentration.
• To collect data in a controlled environment and also use our CO₂ Gas Sensor, we recommend purchasing either the BioChamber 250 (250 mL capacity) or the BioChamber 2000 (2 L capacity). The BioChambers have two openings with grommets so that you can insert both the CO₂ Gas Sensor and the O₂ Gas Sensor to take measurements of the atmosphere inside the BioChamber simultaneously.

For more troubleshooting and FAQs, see www.vernier.com/til/1421

If you have watched the related product video(s), followed the troubleshooting steps, and are still having trouble with your O₂ 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.

For information on common repairs for the O₂ Gas Sensor, see www.vernier.com/til/1605

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

The BioChambers have two openings with grommets so that you can insert both the CO₂ Gas Sensor and the O₂ Gas Sensor to take measurements of the atmosphere inside the BioChamber simultaneously.