Additional specifications and description
Is there sufficient fresh air supply?
People produce CO2 or carbon dioxide while breathing. That makes CO2 concentration a good indicator for the occupancy and activity level in a space. The higher the occupancy or activity level, the more fresh air supply is required to maintain good indoor air quality. That is why in many applications, CO2 sensors are used as an indicator for the ventilation requirements. Next to CO2, this sensor also measures temperature, relative humidity and ambient light level. The measured temperature, relative humidity and CO2 level are available via the three analogue outputs and via Modbus RTU. The dew point and ambient light level are available via Modbus RTU communication.
Three analogue outputs to transmit the measured values
This sensor has three analogue 0-10 Volt outputs. Each of them transmits one of the measured values. E.g. by default, output 1 will transmit 0 Volt at 0 °C and 10 Volt at 50 °C. Each output value varies proportionally in function of the measured temperature, humidity or CO2 concentration. The measured temperature is available via output 1, relative humidity via output 2 and CO2 concentration via output 3. By default the output type is 0-10 Volt. Other output types can be selected via de Modbus holding registers. The 0-10 Volt outputs can be used to control an EC fan, a damper actuator or an AC fan speed controller.
Visual indication of the measured value
This HVAC transmitter offers a clear, visual indication of the CO2 level via the green, yellow and red LED. The green LED indicates that the CO2 level is within range - there is sufficient fresh air supply. When the CO2 level enters the alert range, the yellow LED lights up. Red means: CO2 out of range or insufficient fresh air supply. The ranges can be adjusted via the Modbus holding registers. The LED indicators can visualize the status of one of the three measured values, by default CO2.
This sensor offers you the choice to connect it via the cage clamp terminal blocks or via the RJ45 connector. Supply voltage and Modbus RTU communication can be connected via the RJ45 connector. Via the terminal blocks it is possible to connect the outputs, Modbus RTU communication and the supply voltage. Never connect the supply voltage via the RJ45 connector and the terminal blocks simultaneously! The supply voltage is 24 VDC. The ground terminals of the power supply (V-) and output (GND) are internally not connected. This means that a 4-wire cable is required to connect this sensor. Most 24 VDC power supplies offer protection against short circuit, overload and overvoltage. A 24 VDC supply voltage increases the safety and reliability of your installation.
Self-calibrating to compensate sensor drift
NDIR or Non-dispersive Infrared technology is used to measure the CO2 level. This technology offers a low life-cycle cost and a precise and stable long-term operation. This NDIR CO2 sensor is self-calibrating. The ABC logic self-calibrating algorithm is by default enabled. This algorithm is designed to be used in applications where CO2 concentrations will drop to outside ambient conditions (400 ppm) at least one time (15 minutes) in a 7day period, which is typically seen during unoccupied periods. The sensor will reach its operational accuracy after 25 hours of continuous operation at a condition that it was exposed to ambient reference levels of air at 400 ppm ± 10 ppm CO2.
This sensor can be installed indoors on a wall or on a surface. The mounting holes are adapted to standard European wall mounting boxes. The sensor can be attached to the wall mounting box with two screws. The sensor enclosure will cover the entire wall mounting box. To ensure optimal performance, the sensor should be protected from direct sunlight.
Enclosure with contemporary design
The enclosure is designed for indoor use. It offers an IP30 protection against ingress of dust and moisture. The enclosure is designed and manufactured in-house in Sentera Plastics. It is exceptionally strong thanks to the use of high quality r-ABS plastic. Thanks to its contemporary modern design, this sensor can be used in most interior styles.