Additional specifications and description
Toxic gas monitoring in air ducts
CO and NO2 are toxic gases that are released by cars and other vehicles. They are especially a danger in underground parking garages. In this environment, a smart ventilation system must detect and prevent the accumulation of these toxic and deadly gases. It can do this by supplying fresh air in the garage when concentrations of CO or NO2 are rising. This duct sensor measures temperature and relative humidity and it monitors the trend of CO and NO2 concentration in air ducts. Based on the temperature and humidity, the dew point is calculated. This sensor will function best if it is installed in a straight section of the air duct. Avoid installing the sensor in turbulent air zones nearby filters, fans, cooling coils, etc. Position the sensor towards the airflow direction. Please consult the mounting instructions for more detailed information.
Detect toxic gas concentrations
Next to Carbon monoxide (CO) and Nitrogen dioxide (NO2), this sensor will also detect changes in concentration of following gases: Ethanol, Hydrogen, Ammonia and Methane. When the concentration of these gases increase, the sensor output value will increase to increase the supply of fresh air. When the supply of fresh air reduces the concentration of toxic gases, the sensor output value will decrease again. The toxic gas sensor element is calibrated and tested in our factory. It doesn't require recalibration.
Modbus RTU communication
The measured temperature, relative humidity, dew point and the trend of the toxic gas levels are available via Modbus RTU communication. This sensor doesn't have any analogue outputs. This makes the sensor simpler and more cost efficient. Via the Modbus input registers, all measured values and the sensor status can be read out. Via the Modbus holding registers, all the sensor's settings can be adjusted. An overview of all Modbus parameters is available in the Modbus register map which can be downloaded via the link above.
How to install a duct sensor?
Sentera duct sensors are suitable for mounting in these two ways: using a flange or not using one. When the sensor is mounted on round ducts, the flange is required. The flange can be discarded if the duct is rectangular. Mount the opening of the sensor probe in the middle of the duct. The probe opening must be positioned in the same direction as the airflow for the sensor to optimally work. This allows the air to enter and exit the probe opening smoothly. Make sure that the sensor is installed in a place where only purified air passes. Impurities can disrupt the airflow over the sensor element and negatively affect its operation.
Reduced installation time One RJ45 connector is all it takes to connect this sensor! Modbus RTU communication and 24 VDC power supply are connected via one UTP cable - we call it Power over Modbus or PoM. All measured values are available via Modbus RTU communication. To facilitate wiring, we recommend to use the Sentera 24 VDC power supplies with RJ45 connector. These power supplies offer protection against short circuit, overload and overvoltage. A 24 VDC supply voltage increases the safety and reliability of your installation.
We use sensor elements and components of the highest quality. This ensures the long-term stability and accuracy of this HVAC transmitter. The enclosure offers IP54 protection against ingress of dust and moisture. The sensor element is integrated in the probe of the duct sensor. This probe has an opening to have direct contact between the air flow and the sensor element. The sensor probe offers IP20 protection.