Dew Point Sensors for Compressed Air Systems
Moisture is the enemy of your compressed air system because it causes rust and corrosion that can degrade compressed air quality and damage downstream equipment. Dew point sensors, which provide continuous monitoring of moisture content, can prevent this potentially costly problem, helping increase reliability, extend equipment life, and optimize the performance of your compressed air system.
As your compressed air partner, JHFOSTER can provide the technology and expertise to integrate these critical components into your compressed air system.
Why Do I Need a Dew Point Sensor?
Dew point sensors are used to monitor and control moisture levels in the air, providing a continuous method of dew point protection. But why are dew point sensors so important?
During the compression process, air compressors draw in warm humid ambient air, the air is heated and becomes saturated with moisture during the compression process and produces water vapor that eventually condenses into liquid water as it passes through the aftercooler and/or wet receiver tank. The moisture that results can enter the compressed air system and cause rust, corrosion, and contamination, which can damage air system components and downstream equipment and compromise the quality of produced air and finished products.
Dew point is the temperature at which the water vapor in the compressed air becomes liquid water, so monitoring dew point with a dew point sensor is essential to preventing corrosion and contamination within the air compression system. And, in the food and beverage, electronics, medical device, pharmaceutical, and other manufacturing industries where compressed air quality testing is required to ensure pure air, dew point monitoring is key to ensuring compliance.
How Do Dew Point Sensors Work?
Different types of dew point sensor technologies may be used in compressed air systems. The two most common dew point sensor types for industrial applications have different operating principles.
Chilled Mirror Hygrometer
Chilled mirror sensors operate on the principle of condensation. Air is passed over the sensor and cooled until the dew point is reached. When the water vapor condenses, the sensor records the temperature and calculates the dew point based on this temperature.
Capacitive Sensors
Capacitive sensors, such as metal oxide capacitive sensors, measure the change in capacitance caused by the moisture on the sensor’s dielectric layer and use this change to calculate the dew point. Capacitive sensors are the standard method for industrial compressed air applications because they are more robust and reliable in harsh environments.
The Importance of Dew Point Sensor Calibration
Like all other industrial equipment, dew point sensors require periodic checks for functionality. Calibration ensures that the sensor is not experiencing drift and that it is reliably measuring dew point, so you can be sure your dew point measurements are accurate.
Calibration is especially important in industries, such as food and beverage, medical device manufacturing, and electronics, that must adhere to International Standards Organization (ISO) standard 8573-1 for compressed air quality.
Calibration compares the output of the sensor against a reference instrument to determine the accuracy of the reading, enabling correction to bring the sensor’s readings in line with the reference reading. The sensor manufacturer will provide a recommended calibration schedule, but sensors in harsh environments may require more frequent calibration.
Dew-point sensor calibration can be performed in-house, but purchasing a precise reference instrument can be costly. Sensors can also be sent back to the manufacturer or to an accredited lab for calibration.
JHFOSTER’s service and support team is your trusted partner for maintenance, calibration, and support throughout the lifecycle of your compressed air system. Ready to optimize your compressed air system performance and ensure the production of clean, dry compressed air? Contact us for assistance selecting and integrating a dew point sensor solution.
