DT039 CO2 Gas Sensor

DT039 CO₂ Gas Sensor

Type:
CO₂ Gas Sensor

Range:
0-5000 ppm CO₂

Sensor Description:

As CO₂ absorbs infrared light, the CO₂ sensor consists of a tube containing an infrared source at its one and an infrared detector at its other end. The infrared detector detects the infrared light not having been absorbed by CO₂ between source and detector. The tube with the infrared sensing element is connected to a box containing the electronics and the connector to the data logger.

How it works:

The infrared source consists of a hot metal filament. As infrared radiation causes heating, The infrared detector measures the temperature increase caused by the amount of infrared radiation not being absorbed by CO₂. The higher the concentration of the absorbing CO₂ gas in the tube is, the less radiation is going to reach the detector, i.e. the temperature increases accordingly less. The temperature increase in the infrared sensor produces a voltage being amplified and read into the data logger. When the sensor is collecting data, you can see the IR source blinking on and off - it takes a new reading about once every second. It is recommended to perform line fits as the measurement will record the 'pulsing' of the IR source resulting in a noisy line.

Calibration:

The DT039 ships fully calibrated, no further calibration is needed as it understands that the CO₂ concentration in the air is 400±40 ppm. Although it is possible to calibrate the sensor as follows:
1. Place the 250 cc bottle together with your sensor outside your building long enough to make sure that its contents are replaced with fresh air. The calibration is based on the fact that the outside air contains 400 ppm.
2. Insert the sensor into the gas sampling bottle containing fresh outside air. Do this by holding the rubber stopper of the sensor and not the bottle.
3 . Connect the sensor to your data logger and let it warm up for at least 90 seconds. Follow the reading on the data logger's display or on the software interface to ensure stability prior to the calibration.
4. Push the CAL button on the sensor case with a pencil point. Release the button immediately after the red LED blinks rapidly three times. After about 40 seconds, the reading should stabilize at a value of about 400±40 ppm. If the reading is significantly lower or higher than 400 ppm, press the button again to repeat the process.

What is it used for:

You are able to measure:

Increases in carbon dioxide levels from small animals and insects.
Changes in carbon dioxide concentration in a plant terrarium during photorespiration and photosynthesis cycles.
CO₂ levels during cellular respiration of peas and beans.
Changing carbon dioxide levels in a classroom.
The rate at which carbon dioxide is removed from an enclosed atmosphere using sodium hydroxide or potassium hydroxide.
The rate of production of carbon dioxide in a chemical reaction between hydrochloric acid and sodium bicarbonate.
The rate at which carbon dioxide gas diffuses through a gas diffusion tube.
The production of carbon dioxide during fermentation or respiration of sugars.

Specifications:

Measurement Range: 0-5000 ppm
Accuracy: (standard pressure, 1 atm):
- ± 100 ppm in the range 0-1000 ppm;
- ± 10% of reading in the range of 1000-5000 ppm.
Resolution: 9.77 ppm CO₂.
Response time: 95% of full-scale reading in 120 seconds.
Warm-up time: 90 seconds (maximum).
Pressure effect: 0.19% of reading/mm of Hg from standard pressure.
Output signal range: 0-2.5 V
Output impedance: 1 kW
Input potential: 5V (±0.25 V)
Gas sampling mode: Diffusion
Normal operating temperature range: 25°C (±5°C)
Operating humidity range: 5-95%, non-condensing
Storage temperature range: -40 to 65°C
Calibration information:
- Slope (gain): 2000 ppm/V
- Intercept (offset): 0 ppm
- Live calibration, performed by push button outside of closed rooms.
Dimensions:
- Probe box: 26 ´ 53 ´ 73 mm
- Sensor tube: 13-mm OD and 75-mm length
- Total length of CO₂ Gas sensor: 147 mm.