Vernier Tech Info Library TIL #1366

CO2 Gas Sensor Troubleshooting and FAQs

CO₂ Gas Sensor, order code CO2-BTA, $249.00
Specifications and User Guide

TROUBLESHOOTING
NOTE: There are two types of CO2 Gas Sensors. One model was sold up to ~1/2007. The new model was sold after 1/07 and replaces the old. There are specifications for both models in this TIL.

-Primary Test: Plug in the sensor, start up the data-collection program and allow the sensor to warm up for at least 90 seconds. Blow directly on the shaft of the sensor. You should see an increase in CO2 levels. The older model sensor will max out at 5000 ppm the newer will max out at 10,000 ppm if set to the Low Range and 100,000 ppm if set to the High Range.

-Secondary Test: Germinate some peas overnight. Place 30 peas in the Nalgene bottle that ships with the CO2 Gas Sensor. Allow the sensor to warm up for 90 seconds and collect data. You should see a steady increase in CO2 levels.

RELATED TIL ENTRIES
-TIL 1134: Tips for using the CO2-O2 Tee
-TIL 1020: What are the CO2 Gas Sensor power issues? Can I use two CO2 Gas Sensors at the same time?

SPECIFICATIONS
- new order code: CO2-BTA
- old order code: CO2-DIN

- Measurement range: 0 - 5000 ppm CO2 (old model); 1-10,000 ppm and 0-100,000 ppm (new model)
OLD MODEL SPECS
- Accuracy (at standard pressure, 1 atm):
+/- 100 ppm in the range of 0-1000 ppm
+/- 10% of reading in the range of 1000 - 5000 ppm.
- Typical Resolution, old model: 20 ppm
- Response Time: 95% of full-scale reading in 120 seconds
- Warm-up Time (connected to powered interface): 90 seconds
- Output signal range: 0 - 2.5 V
- Output impedence: 1 k
- Input potential: 5 V (+/- 5 deg C)
- Gas sampling mode: diffusion
- Normal operating temperature range: 25 deg C (+/- 5 deg C)
- Storage temperature range: -40 to 65 deg C

NEW MODEL SPECS
-- Accuracy
+/- 100 ppm or +/- 10% of reading (low range)
+/- 100 ppm or +/- 20% of reading (high range)
Typical Resolution
-13-bit resolution (SensorDAQ): 1.5 ppm (low range); 15 ppm (high range)
-12-bit resolution (LabPro, LabQuest, Go! Link, ULI, or SBI): 3 ppm (low range); 30 ppm (high range)
-10-bit resolution (CBL 2): 12 ppm (low range); 120 ppm (high range)
-Response Time: 95% of full scale reading in 120 seconds
-Warm up time: 90 seconds
-Pressure effect: 0.19% of reading/mm Hg from standard pressure
-Output signal range: 0 - 4.0 V
-Input potential: 5V (+/- 0.25 V)
-Gas sampling mode: diffusion
-Normal operating temperature range: 25 deg C (+/- 5 deg C)
-Operating humidity range: 5 - 95% (non-condensing)
Storage temperature: -40 to 65 deg C

CALIBRATION
- Calibrate? Usually no.
- If you do find that you need to calibrate your CO2 Gas Sensor, it can be calibrated using one known CO2 level. Note: This calibration method is different from the usual two-point calibration performed using other Vernier sensors. See the Specifications and User Guide for the CO2 Gas Sensor for detailed instructions on how to calibrate.

- If you wish to reset the CO2 Gas Sensor to its factory default calibration values (new model only), press and hold the Calibration button for approximately 5 seconds. The red light will change from flashing to steady. When the light turns off, the sensor will be back to its factory settings for that range.

RELATED VERNIER PRODUCTS
-250 mL Nalgene Bottle w/Lid, order code CO2-BTL, $3.00
-CO₂ to O₂ Tee, order code CO2-TEE, $5.00
BioChamber 250, order code BC-250, $6.00
BioChamber 2000, order code BC-2000, $19.00

Created by: gstahmer on January 19 2005
Last updated by: aplank on May 11 2009