Dew Point Meters for Compressed Air and Gases
Keep Moisture Under Control to Avoid Downtime and Contamination
Moisture can cause equipment damage, contamination, and costly downtime. The use of dew point meters for compressed air and gases is, therefore, important to ensure the air is clean and dry. These meters protect your equipment from problems such as blockages; thus, they guarantee adherence to ISO 8573-1 and ISO 8573-3 standards.
SUTO iTEC Dew Point Meters deliver precise measurements for dew point, pressure, and temperature. With this, you will be able to take control of your compressed air quality effectively.
With more than 20 years of experience, SUTO iTEC is specialized in high-precision dew point sensors for industrial applications worldwide.
SUTO iTEC Dew Point Meters
We offer a wide range of dew point meters designed for precise monitoring of moisture in compressed air and gases. From portable instruments for quick spot checks to fixed sensors for continuous monitoring.
Why Measure the Dew Point of Compressed Air?
Have you ever had a failure of a dryer go unnoticed in your compressed air system, shutting down production?
Compressed air often contains water vapor, which can condense into liquid water droplets if the dew point temperature is not properly controlled. This may result in:
- Corrosion and rust in pipelines and equipment.
- Contamination of products and processes, mostly in sensitive industries like food and pharmaceuticals.
- Lowered efficiency of dryers and other systems.
- Failure to meet the requirements of ISO 8573-1 and hence causing quality and compliance problems.
Measuring the dew point prevents all these problems. It ensures smooth operations and high-quality results.
Types of Dew Point Meters for Compressed Air
Dew point meters come in different designs to suit various applications:
1. Polymer-Sensors
- Ideal for standard applications in refrigeration or desiccant drying systems.
- They measure dew points in the range -60°C to +50°C.
2. QCM-Sensors (Quartz Crystal Microbalance):
- Designed for ultra-low dew points (-100°C to -20°C).
- Perfect for industries requiring high precision, such as electronics and pharmaceuticals.
Polymer + QCM: S220 Dew Point Meter
SUTO iTEC sets itself apart with the S220 Dew Point Meter, which combines Polymer and QCM sensors into a single device. This innovation provides a wider measurement range of -100°C to +20°C, covering both standard and ultra-low dew point applications.
This makes the S220 an ideal choice for highly demanding industries where both accuracy and flexibility in compressed air systems are needed.
Integrated Pressure Measurement
In order to be able to output the pressure dew point according to ISO 8573-1, a conversion must be carried out. This requires a built-in pressure sensor.
Where Should a Dew Point Meter Be Installed
To obtain meaningful and reliable results, dew point should be measured at key locations in the compressed air system
Typical Measurement Points
- After the dryer: The most important point to verify dryer performance and confirm the required pressure dew point before the air enters the distribution network.
- Before critical processes: Installed upstream of moisture sensitive applications to ensure consistent air quality and prevent rejects, contamination or process interruptions.
- At the point of use: Measures the actual dew point at the end of the line to detect moisture pickup in the network caused by pressure drops, insufficient insulation, leaks or local cooling.
Recommended Installation Locations by Device
S211 – Dew Point Sensor for Adsorption dryers
- −60 … +20 °C Td
- Installed after adsorption dryers to verify dryer performance and monitor the achieved pressure dew point in compact or OEM applications.
S215 – Dew Point Sensor for Refrigeration Dryers
- −20 … +50 °C Td
- Typically installed after refrigeration dryers and before moisture sensitive processes to prevent condensation in standard industrial systems.
S220 – Dew Point Meter with High Range
- −100 … +20 °C Td
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Installed after adsorption dryers or before critical processes in applications requiring very low dew points and ISO 8573-1 compliance.
S520 – Portable Dew Point Meter
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−100 … +20 °C Td (Standard) / −60 … +50 °C Td
- Used for temporary measurements after dryers, within the distribution network and at the point of use during service, audits and troubleshooting.
S305 – Dew Point Monitor with Display & Alarm
- −60 … +20 °C Td
- Installed after refrigeration or adsorption dryers for continuous monitoring with local display and alarms.
In which applications are compressed air dew point meters typically used?
Dew point sensors are essential wherever dry process air is critical. They help monitor humidity levels, store measurement data, and trigger alarms or actions when limits are exceeded. This protects the production and ensures consistent air quality.
Applications Where Dry Air Is a Must:
Paint shops
In modern paint systems, spray guns run on compressed air. If water mixes with the paint, it causes visible contamination. A single issue like this can ruin a full day of production.
Pharmaceutical Manufacturing
Moisture-free air ensures compliance with strict regulations and guarantees product purity.
Electronics Production
Humidity can damage sensitive components. Dew point monitoring keeps your products safe and reliable.
Food Industry
Compressed air is used to inflate packaging like chip bags. Any moisture can carry bacteria or make crispy snacks soggy. That’s why dry air is vital.
Packaging Lines
Clean, dry air helps prevent contamination and supports hygienic, high-quality packaging.
Measuring Gases Beyond Compressed Air
SUTO iTEC’s dew point sensors for compressed air are highly versatile and capable of measuring various gases, including:
- Carbon Dioxide (CO₂): Used in food and beverage processing.
- Nitrogen (N₂): Common in manufacturing and packaging.
- Oxygen (O₂): Essential for pharmaceutical and medical applications.
Custom solutions are also available for monitoring humidity, temperature, and dew point in alternative gases, ensuring compatibility with unique industrial requirements.
Contact our experts to find the best solution for your application
Why Calibrate a Dew Point Meter for Compressed Air?
Calibration is an essential aspect in ensuring your dew point sensor is accurate and reliable. Regular calibration helps:
- Corrosion and rust in pipelines and equipment.
- Contamination of products and processes, mostly in sensitive industries like food and pharmaceuticals.
- Lowered efficiency of dryers and other systems.
- Failure to meet the requirements of ISO 8573-1 and hence causing quality and compliance problems.
Measuring the dew point prevents all these problems. It ensures smooth operations and high-quality results. Learn more about our comprehensive service offerings that go beyond calibration.
Frequently asked questions (FAQ)
Why is the dew point sensor responding slowly?
- The sensor was previously exposed to very wet air and needs recovery time.
- Contamination such as oil, particles, or chemicals is slowing moisture exchange at the sensing surface.
- The sample flow is too low or stagnant.
- The sensor is installed in a dead-leg or in a point with poor air exchange.
- The sensing element has aged and no longer meets its original response specification.
- Verify that sufficient sample flow reaches the sensor and that the measuring point is representative.
- Check whether the sensor has been exposed to condensate or oil contamination.
- Compare response after a process step change with the expected sensor behavior from the datasheet.
- Clean or service the sampling system if applicable, but do not damage the sensing element.
- Recalibrate or replace the sensor if long-term drift or aging is suspected.
Why is the dew point reading unstable?
An unstable dew point reading usually means the moisture conditions at the sensor are changing or the measurement conditions are unstable. Possible causes include system instability, poor installation, contamination, or electrical interference.
Possible causes:
- Pressure fluctuations or pulsations affecting the sensor
- Unstable or insufficient sample flow
- Dead volume or poor sample line design
- Condensate, oil mist, or contamination reaching the sensor
- Rapid dryer cycling or changing process conditions
- Insufficient stabilization time after startup or humidity changes
- Electrical noise, poor grounding, or signal interference
- Faults in the analog reading device or wiring
Recommended checks:
- Verify stable pressure and flow conditions
- Inspect installation point and sample line design
- Check upstream filtration and drainage
- Inspect wiring, shielding, and grounding
- Allow enough stabilization time
- Compare with a reference instrument if necessary
- Check for electrical noise using a multimeter or oscilloscope if suspected
Why is the dew point reading too high?
A dew point reading that is too high means the moisture content in the compressed air is above the expected level. This can indicate either a system issue or a sensor/installation problem.
Possible system causes:
- Dryer is undersized, overloaded, or malfunctioning
- Bypass valve is open or leaking
- Measurement point is before the final drying stage
- Pressure or flow conditions are outside the intended range
Sensor and installation checks:
- Verify correct sensor installation and orientation
- Ensure sufficient airflow at the sensor tip
- Check for nearby leaks or unstable pressure
- Inspect the sensor for contamination or calibration drift
- Compare readings with a portable reference dew point meter
Recommended diagnostic approach:
- Verify dryer type and target pressure dew point
- Check if actual flow exceeds dryer capacity
- Inspect filters, drains, separators, and bypass lines
- Review the installation according to the manual
- Confirm readings with a portable reference instrument
- Recalibrate or replace the sensor if necessary
What is the difference between atmospheric and pressure dew point?
Atmospheric dew point is the dew point at no pressure under normal ambient conditions, such as in expanded compressed air. If the air is compressed the moisture contained therein is forced into a smaller volume. Thus, the moisture per unit of volume increases so does the dew point. The pressure dew point is always measured under pressure.
Why has a dew point be checked at the point of use?
Due to the fact that the natural phenomena of equalization (balancing unstable conditions by flow) humidity from the ambient is able to penetrate compressed air piping even the air is pressurized. As a normal compressed air system has countless connection points through which humidity enters the piping. This results in influencing the dew point negatively. The effect has to be considered for applications where the dew point is critical and therefore point of use is the only reliable way to avoid any risks for the production.
At which points in a compressed air system should I measure the dew point?
Measuring air purity at key points in a compressed air system ensures clean, reliable air for all applications. Quality should be checked after filtration to verify that contaminants such as oil, water, and particles are removed. It should also be monitored before distribution points and at critical equipment to ensure that air remains clean throughout the network. The most important location is the point of use, where compressed air directly affects processes and product quality. Regular system wide checks help detect issues early and maintain compliance with required standards.
What is a Dew Point Sensor?
A dew point sensor for compressed air measures the temperature at which moisture begins to condense. Keeping this value low is essential to avoid corrosion, contamination, and equipment damage.
Capacitive dew point sensors are widely used because they are accurate, fast, robust, and cost effective. They work by detecting changes in electrical capacitance as water vapor interacts with the sensor surface. These changes allow the sensor to calculate the dew point of the compressed air.
Capacitive sensors offer several advantages. They provide reliable accuracy, fast response times, and long term stability even in harsh industrial environments. They are also far more affordable than chilled mirror systems and suitable for many industries such as manufacturing, pharmaceuticals, food and beverage, and automotive.
Monitoring dew point is essential to protect equipment, maintain product quality, and ensure efficient operation of compressed air systems.
Overall, capacitive dew point sensors are key tools for maintaining dry and clean compressed air across a wide range of industrial applications.
Why SUTO iTEC Dew Point Meters?
SUTO iTEC’s compressed air dew point monitoring is trusted for their:
- High precision: Accurate results across a wide range of temperatures and pressures.
- Unique technology: Combining Polymer and QCM sensors, the S220 is unmatched in its flexibility.
- Durability in every detail: Durable, low-maintenance design for harsh environments
- After-sales support: Reliable customer service and expert guidance to ensure optimal performance.
- More than 20 years of experience: SUTO iTEC provides dew point meter solutions for various industries across the globe.
Our experts at SUTO iTEC will be happy to advise you and help you find the right measuring device for your requirements. Contact us for a personal consultation.
