Volatile organic compounds (VOCs) are ubiquitous indoors, and different organic compounds can pollute a room at the same time. The typical sources of VOC pollution within a home are listed in Table 2. Because many volatile organic compounds have similar chemical structures, it can be difficult to differentiate them in a VOC gas mixture. For more information about the different types of TVOC sensors, please see the Application Note.
Test gases for TVOCs
TVOC, or Total Volatile Organic Compounds, are organic compounds that turn to gas at room temperature. In an ideal situation, these concentrations should not exceed 0.6 mg/m3. However, since these pollutants can be present in large quantities in buildings, it is difficult to measure the concentration of these compounds. To help with this, the ISO norm for indoor air quality provides standardized test methods for VOC detectors. TVOC levels are measured by comparing a simulated VOC mixed gas with two test gases: m-xylene and n-octane. Each of these gas mixtures represents a different type of saturated hydrocarbon.
For this purpose, we developed a tvoc sensor that measures two gas samples at once. This sensor is integrated with a based microcontroller and enables data acquisition, storage, and monitoring. In addition, extensive testing of the sensor was conducted in an automated sample preparation laboratory and a chemical hood.
Types of TVOC sensors
TVOC sensors are used to measure the concentration of volatile organic compounds (VOCs) in the atmosphere. They measure these chemicals through their electrical resistance. TVOC sensors can be analog or RS485-compatible and have multiple outputs. Some of them can also be wall-mounted. They can also be used in harsh environments.
To choose the right one, it is important to understand the different types and the functions of these sensors. For example, a sensor that measures only the concentration of VOCs in the atmosphere is not as accurate as one that measures both VOCs and IAQ. However, the combination of these two technologies allows for better accuracy and minimizes false-positive results.
TVOC sensors are capable of measuring a wide range of volatile organic compounds and other gases relevant to indoor air quality. They can also be production-calibrated. While many VOCs are produced by humans, others have natural sources and are not as harmful as many people think. Building materials can also emit VOCs, which can be reduced with appropriate precautionary measures. Types of TVOC sensors are useful for a variety of industries and applications.
Accuracy of TVOC sensors
TVOC sensors are portable devices that measure the total mixture of volatile organic compounds. However, their response to different types of compounds can vary. This can lead to inflated final readings. For example, some VOCs are more hazardous than others. This can lead to a high reading for one VOC while a low reading for another VOC.
One way to improve TVOC sensor accuracy is to calibrate it with known sources. You can calibrate your TVOC sensor by entering the source of the VOC. The calibration process takes between 24 and 48 hours. During this time, the readings will fluctuate.
Reliability of TVOC sensors
The SGP is an example of a TVOC sensor that is designed to detect various types of VOCs, including TVOC. It uses ethanol as a calibration standard, which serves as a stable proxy for TVOC. The ethanol calibration is useful for calibrating the device against an ISO-standard two-component VOC mix that simulates ambient concentrations of TVOC.
Reliable Controls SMART-Sensors with VOC are backed by a five-year warranty and support network of Authorized Dealers worldwide. They measure the concentrations of volatile organic compounds in indoor air and help to improve building occupant health.
Testing methods for TVOC sensors
There are two basic testing methods used for TVOC sensors. The first method involves ionization and uses ultraviolet light to ionize molecules. Then, the sensor measures the electron concentrations of the ions. In other cases, flames may be used to ionize molecules. The second method uses a solid-state sensor, such as metal-oxide semiconductors or electrochemical sensors. The benefits of this method include high sensitivity and portability, but limited selectivity.
Conclusion
Testing methods for TVOC sensors can also be performed on SGP sensors. These devices can measure a wide variety of VOCs, including TVOC. During calibration, the SGP’s response to ethanol can be compared with the response of TVOC. The results of the calibration can be used to determine whether the TVOC sensor is sensitive enough. Once the calibration is complete, the sensor can be used for TVOC application.
