MKS 626, 627, 628 Series Pressure Transducers

1. Introduction

In precision industries such as semiconductor manufacturing, aerospace, pharmaceuticals, and industrial automation, accurate pressure measurement is critical for maintaining process stability and efficiency. The MKS 626, 627, and 628 Series Pressure Transducers are widely used for high-precision pressure monitoring and control in vacuum systems and industrial applications. These transducers are known for their exceptional accuracy, long-term stability, and resistance to harsh operating environments.

Each model within the series is engineered to meet specific pressure measurement requirements, offering a range of features such as absolute, gauge, and differential pressure sensing, temperature compensation, and digital output capabilities. This article provides a comprehensive analysis of the design, working principles, applications, and advantages of these transducers, along with insights into their future developments.

2. Overview of MKS 626, 627, 628 Series

The MKS 626, 627, and 628 series consists of high-performance pressure transducers designed for precise and repeatable pressure measurement in demanding applications. Each model within the series has specific performance characteristics tailored to different measurement environments:

Key Design Considerations:

• Compact and robust construction for reliable operation in industrial settings.
• High-purity materials to ensure contamination-free measurements in semiconductor fabs.
• Digital and analog output options for seamless integration into automation systems.
• Minimal drift and high repeatability, ensuring long-term stability.

The MKS 626 and 627 models are widely adopted in vacuum applications, while the MKS 628 is designed for precise differential pressure monitoring in cleanrooms and controlled environments.

3. Working Principle and Pressure Measurement Technology

The MKS 626, 627, and 628 Series Pressure Transducers utilize advanced capacitive and piezoresistive sensing technologies to achieve high accuracy and stability in pressure measurements.

Key Measurement Technologies:

1. Capacitive Sensing:

   • Used in high-precision absolute and differential pressure transducers.
   • Works by detecting changes in capacitance as pressure deforms a diaphragm.
   • Offers high sensitivity and low hysteresis, making it ideal for vacuum and low-pressure measurements.

2. Piezoresistive Sensing:

   • Utilizes a silicon-based strain gauge that alters electrical resistance in response to pressure.
   • Provides fast response time and excellent linearity, making it suitable for industrial and automation applications.

3. Signal Processing and Output:

   • The transducers feature temperature compensation to minimize measurement drift.
   • Digital signal processing (DSP) enhances accuracy and reduces noise in readings.
   • Available with both analog (0-10V, 4-20mA) and digital (RS-232, RS-485) outputs for flexible integration.

These technologies enable MKS pressure transducers to provide stable, repeatable, and interference-resistant measurements, even in dynamic operating conditions.

4. Key Features and Performance Parameters

The MKS 626, 627, and 628 series are designed to deliver superior performance in demanding environments. Below are some of their key features and performance benchmarks:

Key Features:

✅ High Accuracy: Measurement precision up to ±0.15% of full scale.
✅ Broad Pressure Range: Supports ultra-low vacuum (10⁻⁴ Torr) to high-pressure applications (1000 Torr).
✅ Temperature Compensation: Built-in algorithms ensure minimal drift due to temperature fluctuations.
✅ Corrosion Resistance: Made from 316L stainless steel and Inconel for durability in harsh environments.
✅ Multiple Output Options: Compatible with analog (4-20mA, 0-10V) and digital (RS-232, RS-485, EtherCAT) interfaces.
✅ Fast Response Time: Capable of millisecond-level response rates for real-time process adjustments.

Performance Benchmarks:

The combination of high precision, robustness, and real-time output capabilities makes these transducers essential for modern process control applications.

5. Applications of MKS 626, 627, and 628 Series Pressure Transducers

The MKS 626, 627, and 628 Series Pressure Transducers are utilized across various high-precision industries where accurate pressure monitoring is crucial for process stability, efficiency, and quality control. Below are some key application areas:

5.1 Semiconductor Manufacturing

In semiconductor fabrication, maintaining precise pressure levels within vacuum chambers is critical for wafer processing. These transducers are used in:

• Etching and Deposition Systems: Ensuring optimal chamber pressure during plasma etching and chemical vapor deposition (CVD) processes.
• Lithography Equipment: Regulating vacuum pressure to avoid contamination and defects in photolithography.
• Leak Detection & Vacuum Monitoring: Maintaining cleanroom vacuum integrity and detecting leaks in process chambers.

5.2 Industrial Vacuum Systems

Industries such as pharmaceuticals, metallurgy, and food processing use vacuum systems for drying, coating, and packaging. The MKS pressure transducers help:

• Optimize vacuum pump performance.
• Maintain consistent pressure in vacuum furnaces and freeze dryers.
• Improve efficiency in vacuum packaging for perishable goods.

5.3 Aerospace & Defense

• Altitude Simulation: Used in test chambers to simulate high-altitude conditions for avionics and aerospace components.
• Fuel System Monitoring: Ensuring precise pressure control in spacecraft and aircraft fuel delivery systems.

5.4 Research and Development Laboratories

• Precision Experiments: Used in high-precision physics, material science, and chemical research requiring controlled pressure environments.
• Environmental Chambers: Maintaining exact atmospheric conditions for product testing and scientific studies.

5.5 Cleanroom and Pharmaceutical Industries

• Differential Pressure Monitoring: The MKS 628 Series is widely used in cleanroom environments to ensure proper airflow control.
• Sterile Processing Equipment: Controlling pressure in sterilizers and aseptic processing systems.

These applications highlight the versatility and reliability of MKS transducers in high-precision industries.

6. Advantages of Using MKS 626, 627, and 628 Series Pressure Transducers

The MKS pressure transducers offer several competitive advantages over other pressure measurement solutions:

6.1 High Precision and Stability

• Provides accuracy up to ±0.15% of full scale.
• Excellent repeatability and minimal drift, ensuring long-term stability in continuous operations.

6.2 Wide Pressure Measurement Range

• Capable of measuring pressures from 10⁻⁴ Torr (ultra-high vacuum) to 1000 Torr.
• Supports absolute, gauge, and differential pressure measurements, making them adaptable across different systems.

6.3 Robust Construction for Harsh Environments

• Manufactured with stainless steel and corrosion-resistant materials for durability.
• Designed to withstand high temperatures, pressure fluctuations, and chemical exposure.

6.4 Seamless System Integration

• Offers both analog (4-20mA, 0-10V) and digital (RS-232, RS-485, EtherCAT) interfaces.
• Easily integrates with PLC, SCADA, and industrial automation systems.

6.5 Fast Response Time

• With response times as fast as <10ms, these transducers allow real-time adjustments in dynamic industrial processes.

These advantages make the MKS 626, 627, and 628 series an industry benchmark for precision pressure measurement.

7. Comparison of MKS 626, 627, and 628 Series with Competing Models

To provide a clearer understanding of the strengths of MKS transducers, the following table compares them to competing models from INFICON and Baratron:

The MKS series outperforms competitors in terms of accuracy, response time, and integration capabilities, making them the preferred choice for semiconductor and precision industries.

8. Conclusion

The MKS 626, 627, and 628 Series Pressure Transducers are among the most reliable and accurate pressure measurement solutions available today. Their high precision, robust design, and seamless system integration make them indispensable for semiconductor manufacturing, vacuum systems, aerospace, cleanrooms, and industrial automation.

By leveraging cutting-edge sensing technologies and offering superior stability, these transducers help industries achieve better process control, reduced downtime, and enhanced product quality. As technology evolves, MKS continues to lead the field by integrating smart features and improving measurement capabilities to meet the demands of next-generation manufacturing.

For industries requiring reliable, high-performance pressure measurement, the MKS 626, 627, and 628 series remain a top-tier choice.