Process Sensing Technologies (PST), based in Ely, Cambridgeshire, UK, offers a range of oxygen and moisture measurement analysers developed to ensure the highest safety and quality in metal Additive Manufacturing processes. The systems are said to provide a means of achieving precision and maintaining build consistency, which is critical to successful production
Oxygen levels in the build chamber can significantly impact quality, explains PST. Excess oxygen can lead to oxidation, compromising the integrity and strength. To prevent oxidation, the oxygen concentration should typically be below 500 ppm for metal Additive Manufacturing processes such as Laser Beam Powder Bed Fusion (PBF-LB).
PST’s oxygen analysers have been specifically designed to be integrated into the Additive Manufacturing machine manufacturer’s control and safety systems. These analysers provide real-time monitoring and control, maintaining optimal oxygen levels during the build process, and can trigger inert gas purges (like argon or nitrogen) to maintain low oxygen levels. When measuring oxygen, PST has sensors capable of detecting oxygen from as little as 1 ppm. Operating ranges from 0-10 ppm to 0-25% with a response time T90<15 seconds.
For ease of use and compact design, PST offers the Microx Oxygen Analyzer, an integrated solution featuring three configurable alarm contacts, an LCD screen displaying O2 concentration, a remote sensor and three analyser mounting options for flexibility. Its zirconia sensor performance is proven in the harsh environment of an Additive Manufacturing build chamber.
PST’s zirconia and solid-state technologies have been specially developed for harsh process applications. They can be supplied with SIL2-capable oxygen analysers or transmitters designed to comply with the requirements of IEC 61508 (SIL Capable) for fail-safe oxygen measurement in inert gas blanketing applications.
For example, the SIL-O2 Process Oxygen Analyzer is engineered for highly reliable oxygen measurement in safety-critical applications, including the Additive Manufacturing machine, depowdering system, and sieve station. It includes a DIN rail-mounted control unit with galvanic barrier and a remote electrochemical (solid state) sensor with interconnecting cable (up to 30 m), providing a flexible, easily integrated package.
The inert gas (argon or nitrogen) used to create an oxygen-free environment should have a purity level of 99.99% or higher. Gas purity analysers, such as PST’s Oxydew, can ensure the supplied gas meets the required purity standards, preventing contamination during the building process.
