JLC International is a distributor of not just flowmeters, but also a wide-variety of transmitters, including carbon dioxide transmitters. These devices allow for an accurate measurement of carbon dioxide so as to continuously obtain precise levels.
About Carbon Dioxide (CO2)
Carbon dioxide is a gaseous component of the Earth’s atmosphere. The concentration of CO2 in the natural ambient air is about 0.04% or 400 ppm. With each breath, humans convert oxygen (O2) into carbon dioxide. Although carbon dioxide is invisible and odorless, an increased CO2-content is apparent because humans will notice increased fatigue and reduced concentration. In rooms with high occupancy such as conference rooms and theaters, negative effects become all the more evident. Modern climate control can ensure optimal air quality by using carbon dioxide transmitters to adjust the supply of fresh air based on the measurement of CO2 concentration in the indoor air. CO2 concentration is regarded as an important measure of indoor air quality.
Carbon Dioxide Measurements
CO2 measurements in HVAC applications are based exclusively on the Infrared (IR) absorption principle. There are two methods to measure CO2 concentration with the IR absorption method:
- Non-Dispersive Infrared (NDIR) absorption sensor
- Photoacoustic sensor
NDIR Absorption Sensors
Compared with the photoacoustic sensors, NDIR absorption sensors offer the following advantages: they are less sensitive to pressure variations, vibrations, and acoustic interference. In addition, carbon dioxide transmitters are more compact.
A patented auto-calibration procedure uses two IR-sources with distinct operation cycles: one IR source operates to measure the CO2 concentration and generates an IR signal every 30 seconds. The second IR source, (the reference source), is used for auto-calibration only. This source is activated twice every 24 hours, which leads to virtually no aging and therefore to negligible drift. The quasi drift-free signal of the reference source is used to offset eventual drifts of the measuring source.
The advantages of this two-source, two-beam measuring principle for carbon dioxide transmitters are easy drift compensation with a stable IR-reference source and the use of a simple IR filter (other methods use two IR filters or complicated switchable IR filters) with only one detector required.
JLC International offers carbon dioxide transmitters in a variety of different packages, including:
- CO2 Transmitters for Rooms, including T and %RH Series EE800
- CO2 Transmitters for Agriculture Applications Series EE820
- CO2 Transmitters for Duct Mounting Series EE850
- CO2 Probes for OEM/HVAC Applications Series EE870/EE871
- CO2 Module for OEM/HVAC Applications Series EE893/EE892
The EE800 is for wall mounting in rooms and other spaces visited by humans, such as museums and conference rooms. The EE820 is specifically designed for harsh, demanding applications like stables, greenhouses, warehouses, hatchers, incubators, as well as fruit and vegetable storage. For typical HVAC applications, the duct-mounted EE850 transmitter is the preferred instrument. The available ranges are 0-to-2000/5000/10000 ppm carbon dioxide.
In places where people gather and the carbon dioxide level is measured and controlled, the need for humidity transmitters to measure the level of humidity and temperature is almost imperative to ensure a comfortable work environment.
JLC International strives to provide you with a selection of carbon dioxide transmitters for a variety of different applications. Interested parties who wish to learn more about our transmitters, you can contact us by filling out a contact form or calling 1-888-358-2518.
CO2 Transmitters for Room, incl. T and / or %RH Series EE800
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Specifications
- Carbon Dioxide Range: 0 – 2000 ppm / 0 – 5000 ppm
- Accuracy : < ± (50 ppm + 2% of reading) for 0 – 2000 ppm
< ± (50 ppm + 3% of reading) for 0 – 5000 ppm - Relative Humidity range: 10 – 90 %RH
- Temperature range: 23 – 131 °F (-5 – 55 °C)
- Dewpoint Temperature range: -22 – 131 °F (-30 – 55 °C)
- Outputs: 0 – 5 V / 0 – 10 V / 4 – 20 mA; RS485 – Modbus RTU or BACnet MS/TP
- US-version; will fit electrical outlet box
- Auto calibrate
- Optional display
CO2 Transmitter for Agriculture Applications Series EE820
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Specifications
- Dual wavelength non-dispersive infrared technology (NDIR)
- Carbon Dioxide Range: 0 – 2000 ppm / 0 – 5000 ppm / 0 – 10000 ppm
- Accuracy: < ± (50 ppm + 2% of reading) 0 – 2000 ppm
< ± (50 ppm + 3% of reading) 0 – 5000 ppm
< ± (100 ppm + 5% of reading) 0 – 10000 ppm - Outputs: 0 – 5 V / 0 – 10 V / 4 – 20 mA
- Supply voltage: 24 Vac ± 20% / 15 – 35 Vdc
- Auto calibration / Long-term stability
- High resistance to pollution
- Enclosure Polycarbonate – IP65 / NEMA 4X
- Plug connection optional
CO2 Transmitter for Duct Mounting Series EE850
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Specifications
- Dual wavelength non-dispersive infrared technology (NDIR)
- Carbon Dioxide Range: 0 – 2000 ppm / 0 – 5000 ppm / 0 – 10000 ppm
- Accuracy: < ± (50 ppm + 2% of reading) for 0 – 2000 ppm
< ± (50 ppm + 3% of reading) for 0 – 5000 ppm
< ± (100 ppm + 5% of reading) for 0 – 10000 ppm - Outputs: 0 – 5 V / 0 – 10 V / 4 – 20mA
- Passive Temperature output optional
- Supply voltage: 24 Vac ± 20% / 15 – 35 Vdc
- Auto calibration
- Enclosure Polycarbonate – IP65 / NEMA 4X; probe IP20
CO2 Probes for OEM / HVAC Applications Series EE870 / EE871
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Specifications
- Carbon Dioxide Range: 0 – 2000 ppm / 0 – 5000 ppm / 0 – 10000 ppm
- Accuracy: < ± (50 ppm + 2% of reading) 0 – 2000 ppm
< ± (50 ppm + 3% of reading) 0 – 5000 ppm
< ± (100 ppm + 5% of reading) 0 – 10000 ppm - Digital output E2 (2-wire) probe EE871
- Supply voltage EE871: 4.75 – 7.5 Vdc
- Conversion board EE870: 10 -135 Vdc / 10 – 28.8 Vac
- Analogue outputs EE870: 0 -1 /5 /10 V and 0 (4) – 20 mA
- Extreme low power consumption
- Auto calibration
CO2 Module for OEM / HVAC Applications Series EE893 / EE892
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Specifications
- Carbon Dioxide Range: 0 – 2000 ppm / 0 – 5000 ppm / 0 – 10000 ppm
- Accuracy: < ± (50 ppm + 2% of reading) 0 – 2000 ppm
< ± (50 ppm + 3% of reading) 0 – 5000 ppm
< ± (100 ppm + 5% of reading) 0 – 10000 ppm - Digital output E2 (2-wire)
- Supply voltage: 4.75 – 7.5 Vdc
- Extreme low power consumption
- Auto calibrate
CO2 Measurement Theory
IP / NEMA a comparison
E2 Interface Specification
E2 Interface EE871
E2 Interface EE89
Please note: Manual data files can be quite large, please be patient while downloading.
The manuals are for information purposes only and shouldn’t be used for operating the instrument