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O2 Gas Sensor User Manual

Order Code: O2-BTA

The O2 Gas Sensor can be used to monitor gaseous oxygen levels in a variety of biology and chemistry experiments. The sensor is intended for measuring gaseous, not aqueous, O2 concentrations.

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.

What's Included

  • O2 Gas Sensor
  • 250 mL gas sampling bottle (Nalgene® bottle with lid)

Compatible Software and Interfaces

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

LabQuest
InterfaceLabQuest App
LabQuest 3Full support
LabQuest 2 (discontinued)Full support
LabQuest (discontinued)Full support
Computers
Software
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.
Chromebook
Software
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.
iOS
Software
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 Androidâ„¢ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
Android
Software
InterfaceGraphical AnalysisGraphical Analysis GW
LabQuest Stream (discontinued)Full supportPartial support 1
LabQuest 3Full support 2Full support 2
LabQuest 2 (discontinued)Full support 2Full support 2

Compatibility Notes

  1. Data can be collected using the sensor’s default calibration only.
  2. iOS and Androidâ„¢ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
Arduino
Software
InterfaceArduino
Vernier Arduino® Interface ShieldFull support
LabVIEW
Software
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
Software
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.

Quick Start

  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

Using the Product

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.

Videos

Calibration

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.

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

Specifications

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

Care and Maintenance

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

How the Sensor Works

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.

Troubleshooting

  • 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

Repair Information

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

Accessories/Replacements

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.

Warranty

Warranty information for this product can be found on the Support tab at www.vernier.com/o2-bta/#support

General warranty information can be found at www.vernier.com/warranty

Contact Support

Fill out our online support form or call us toll-free at 1-888-837-6437.

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