Accurate pressure measurement is a fundamental requirement in advanced vacuum and process control environments. From semiconductor manufacturing and thin-film deposition to analytical instrumentation and industrial vacuum systems, pressure stability and repeatability directly impact process yield and product quality.
MKS Capacitance Manometers have become a long-standing industry standard for absolute pressure measurement due to their high accuracy, gas-independent response, and long-term stability. This article provides a comprehensive, technical overview of MKS capacitance manometers, including their working principles, performance advantages, common models, and typical applications.
What Is an MKS Capacitance Manometer?
An MKS Capacitance Manometer is a high-precision absolute pressure sensor designed to measure vacuum and low-pressure gas environments. Unlike thermal or ionization-based gauges, capacitance manometers directly measure physical diaphragm deflection caused by pressure changes.
This measurement approach makes them:
● Gas-type independent
● Highly repeatable
● Exceptionally stable over time
For these reasons, capacitance manometers are widely used as reference pressure gauges in critical processes.
Measurement Principle of Capacitance Manometers
The operating principle is based on capacitance change.
Inside the sensor:
● A thin metallic diaphragm deflects under applied pressure
● The diaphragm forms one plate of a capacitor
● The fixed electrode forms the second plate
● Pressure-induced deflection changes the capacitance
This capacitance change is converted into a highly linear electrical signal proportional to absolute pressure, not relative pressure.
Key Characteristics of the Principle
● True absolute pressure measurement
● No dependence on gas composition
● Minimal temperature sensitivity when temperature-controlled
● Excellent linearity across full scale
This fundamental design explains why MKS capacitance manometers are often chosen for calibration-critical environments.
Why MKS Capacitance Manometers Are Widely Trusted
1. Gas-Independent Accuracy
Unlike Pirani or convection gauges, capacitance manometers respond only to mechanical pressure, not thermal conductivity. This ensures consistent readings across different gases such as nitrogen, argon, hydrogen, or process gas mixtures.
2. High Accuracy and Repeatability
Typical performance includes:
● Accuracy down to 0.25% of reading or better
● Excellent repeatability across thousands of cycles
● Minimal zero drift when properly maintained
3. Long-Term Stability
MKS designs emphasize mechanical robustness and thermal control, allowing gauges to remain stable for extended production cycles without frequent recalibration.
Typical Applications of MKS Capacitance Manometers
MKS capacitance manometers are used across a wide range of high-precision industries.
Semiconductor Manufacturing
● CVD, PVD, and ALD process pressure control
● Etching and deposition chambers
● Load locks and transfer modules
Vacuum Equipment and Tooling
● Vacuum system calibration
● Reference gauges for controller feedback
● Leak detection and system diagnostics
Thin Film and Display Manufacturing
● OLED and LCD deposition processes
● Sputtering systems
● Coating thickness control
Research and Analytical Systems
● Mass spectrometry
● Surface science instruments
● Vacuum test benches
Overview of Common MKS Capacitance Manometer Models
MKS offers a wide portfolio of capacitance manometers optimized for different pressure ranges, mechanical interfaces, and signal outputs. Below are commonly used models in industrial and semiconductor environments.
MKS 628 Series
● High-accuracy, temperature-controlled manometers
● Commonly used in semiconductor process tools
● Excellent long-term stability
Example:
● 628B11TBE1BMKS
MKS 626 Series
● Compact, reliable design
● Widely used in OEM equipment
● Good balance between cost and performance
Examples:
● 626B11TBE
● 626A11TBE10
MKS 622 / 625 Series
● Designed for general vacuum measurement
● Often used in support systems and process monitoring
Examples:
● 622A01TDE
● 625A-14059
Special and Legacy Models
● 627B-22842
● E28B-24565
● E29B-23813
● 124AA-00010BB
● 127AA-00010B
These models are frequently found in installed semiconductor tools, making long-term spare availability critical.
Key Selection Considerations
When selecting an MKS capacitance manometer, engineers typically evaluate:
● Full-scale pressure range
● Accuracy and resolution requirements
● Temperature-controlled vs non-controlled design
● Output signal type (analog, digital)
● Mechanical fitting and flange type
● Compatibility with existing controllers
Choosing the correct model ensures both process accuracy and long-term operational stability.
Maintenance, Calibration, and Lifecycle Support
Although capacitance manometers are known for durability, proper lifecycle management is essential.
Best practices include:
● Periodic zero and span verification
● Controlled warm-up for temperature-stabilized models
● Clean installation to avoid particle contamination
● Availability of compatible spare units for quick replacement
For older or discontinued models, sourcing technically verified replacements becomes especially important to avoid extended tool downtime.
Conclusion
MKS Capacitance Manometers remain one of the most accurate and reliable solutions for absolute pressure measurement in vacuum and low-pressure environments. Their gas-independent operation, high repeatability, and long-term stability make them indispensable in semiconductor manufacturing, vacuum systems, and advanced research applications.
Understanding their working principles, model differences, and application requirements allows engineers and facilities to maintain precise pressure control and consistent process performance over time.
As a professional supplier specializing in MKS Capacitance Manometers and compatible models, we focus on providing technically verified instruments and practical support knowledge to help customers maintain stable, high-accuracy vacuum measurement systems throughout the entire equipment lifecycle.
