Differential Pressure Sensors: Cleanroom Guardians

Clean and isolation rooms are indispensable in industries where precision and purity are paramount. These controlled environments, from healthcare facilities to semiconductor manufacturing, are designed to maintain specific air pressure levels and minimize particulate contamination. The success of operations in these spaces hinges on keeping external pollutants at bay and ensuring that the internal atmosphere meets rigorous standards.

Many Types of Clean and Isolation Rooms

The applications of clean and isolation rooms span various sectors, each with its unique requirements:

• Healthcare: Hospitals utilize isolation rooms to prevent the spread of infectious diseases and operating rooms to protect patients during surgery.
• Pharmaceuticals: Pharmaceutical plants rely on clean rooms to prevent drug contamination.
• Biotechnology: Biological labs use clean rooms to conduct research in a contaminant-free environment.
• Electronics: Wafer fabrication facilities and electronic product manufacturing plants require clean rooms to prevent defects in delicate components.
• Research and Development: R&D laboratories employ clean rooms to conduct experiments under controlled conditions.

These rooms provide positive or negative pressure based on the air pressure relative to the surrounding environment. Positive-pressure rooms prevent the ingress of contaminated air, while negative-pressure rooms prevent the escape of harmful agents.

Positive pressure rooms focus on maintaining sterility. Preventing external contamination is paramount in environments like pharmaceutical compounding or semiconductor manufacturing. Differential pressure sensors ensure a consistent overflow of clean air, keeping contaminants at bay.

Figure 1 – Hospital Operating Room

In contrast, negative pressure rooms focus on containing hazardous substances. In facilities dealing with infectious agents or hazardous chemicals, negative pressure rooms prevent harmful particles from escaping. Differential pressure sensors monitor the environment to ensure safety and compliance with health standards.

Beyond air pressure, many laboratories and manufacturing facilities require a clean production environment where airborne particles, humidity, temperature, and airflow can be measured and controlled. These facilities must maintain specific parameters to ensure environmental conditions don’t compromise product research, development, or production. Since 2001, these clean rooms have been rated based on the ISO 14644-1 standard, which classifies them based on the maximum acceptable number of particles by size in the air per cubic meter.

Figure 2 – R&D Clean Room

The Role of Differential Pressure Sensors in Clean and Isolation Rooms

Differential pressure sensors measure the difference in air pressure or particles from two sources. They play a critical role in clean rooms and similar applications where maintaining strict pressure differentials is essential to preventing contamination. For example, changes in either pressure or air quality when someone enters a positive-pressure room can impact the effectiveness of what is being examined.

The purpose of the clean room is to maintain fixed air pressure and/or eliminate contamination by dirt particles, some of which potentially contain microorganisms or toxins. Accurate differential pressure levels ensure clean rooms work as intended. Careful measurement and monitoring of pressure both inside and outside the clean room confirm the differential remains within the acceptable range.

However, like most electromechanical devices, differential pressure sensors are sensitive to many external factors, including noise, humidity, temperature, and physical positioning. Sensors that reduce the impact of external factors will provide the most accurate readings to ensure the effectiveness of clean and isolation rooms.

Superior Sensor’s Technology Advantage

Superior Sensor Technology’s NimbleSense^TM architecture represents a significant leap forward in differential pressure sensing. By incorporating a highly differentiated advanced pressure sensing system with the ability to integrate optional building blocks, we combine the highest accuracy and reliability with application-exclusive features. With unique technology deployed in our HV and ND Series of differential pressure sensors, Superior’s products offer many advantages for clean rooms, isolation rooms, and other air quality applications.

Unmatched Accuracy

Sensor accuracy is critical for sealing clean rooms and isolation rooms correctly. Determining even the smallest leaks is essential for guaranteeing a clean manufacturing/lab environment or isolating airborne contaminants. Superior’s HV and ND Series of differential pressure sensors have the industry’s leading accuracy, to as close as within 0.05% of the selected pressure range.

Robust Noise Reduction

External noise can adversely affect sensor performance. Our advanced digital filtering technology mitigates this issue, ensuring that our sensors provide reliable readings free from interference. Superior’s pressure sensors eliminate the noise before it becomes an error signal that can lead to inaccurate readings.

Figure 3 – Measuring Air Pressure to Verify Seal Integrity

Position Insensitivity

In applications where sensors may be moved or reoriented, our unique dual-die implementation ensures consistent accuracy regardless of the sensor’s orientation. Superior’s HV210 and ND210 sensors are ideal for handheld applications such as room/building seal integrity testing, maintaining consistent and highly accurate readings regardless of device orientation.

Integrated 50/60Hz Notch Filter

Our sensors feature a 50/60Hz notch filter to avoid power line interference, maintaining high accuracy even in the presence of external electrical noise. For more details, read the 50/60Hz Notch Filter blog post.

Rapid Response Times

Our sensors stand out in time-sensitive applications with their quick warm-up and response times. The ND Series, for example, is ready in just 80 milliseconds and has update rates as fast as 2.25 milliseconds, ensuring timely and accurate pressure measurements.

Conclusion: A New Standard in Clean Room Monitoring

In clean and isolation rooms, where the margin for error is slim, differential pressure sensors’ role cannot be overstated. They monitor controlled environments to maintain optimal conditions for critical operations.

Superior Sensor Technology’s innovative approach to differential pressure sensing sets a new standard. Our NimbleSense™ architecture, with its unique combination of accuracy, noise reduction, and fast response times, provides an unmatched solution for maintaining the most reliable clean and isolation rooms.

As industries evolve and the demand for precision grows, advanced sensing technologies will only become more important. We are committed to pushing the boundaries of differential pressure sensing, ensuring our clients can confidently operate in their clean and isolation rooms.

For more detailed information, please visit our HV Series and ND Series product pages or contact us.