Caspar Ask Christiansen, Ole Wenzel, Sens4 A/S, Hellebaek, Denmark
Precise and reliable vacuum measurement is essential to achieving consistent, high-quality results in modern vacuum coating processes. Traditionally, this has required a combination of sensors — including ionization gauges — to cover the full vacuum range. However, recent advancements in sensor design and materials now make it possible to significantly extend the functional range and durability of thermal and mechanical gauges, challenging long-standing dependencies on fragile, high-maintenance technologies.
This talk presents recent breakthroughs in vacuum gauging that enable wide-range, gas-independent measurement without the need for ionization gauges. Central to this development is the integration of MEMS-based Pirani sensors with high-resolution piezo resistive diaphragm sensors and capacitance diaphragm gauge sensors, enabling seamless pressure coverage across six decades. The inclusion of automatic zero-offset adjustment of the diaphragm type sensors further reduces drift and eliminates the need for frequent manual zero adjustment, offering huge savings.
To address the challenges of harsh process environments, advanced protective strategies have been implemented. Conformal coatings — such as high-purity Al_₂O₃ applied by atomic layer deposition (ALD) — provide exceptional resistance to corrosive gases, while preserving sensor sensitivity and response time. Novel replaceable baffle designs, further increase the resilience towards sensor contamination. These innovations dramatically extend sensor lifespan and reduce maintenance intervals, lowering total cost of ownership.
Finally, the talk will explore the role of modern digital interfaces, including EtherCAT, in enabling faster, more reliable integration of vacuum gauges into coating system control architectures. Together, these advancements represent a new generation of vacuum sensing solutions — robust, low-maintenance, and fully aligned with the demands of high-throughput, precision coating operations.