Leybold PTR 90 Full-Range Vacuum Gauge
| Brand | Leybold |
|---|---|
| Origin | Germany |
| Model | PTR 90 |
| Measurement Principle | Pirani + Cold Cathode (Penning) |
| Range | 1×10³ to 1×10⁻⁸ mbar |
| Vacuum Port | KF 25, CF 40 |
| Output Interface | RS232 / RS485 (digital), optional analog 0–10 V or 4–20 mA |
| Accuracy | ±30% (1×10⁻⁸–1×10⁻² mbar), ±15% (1×10⁻²–10 mbar) |
| LED Indication | Adaptive pulse-mode pressure display |
| Housing | Compact stainless steel, IP65-rated |
Overview
The Leybold PTR 90 is a fully integrated, active full-range vacuum gauge engineered for continuous, reliable pressure measurement across an exceptionally wide dynamic range—from atmospheric pressure down to ultra-high vacuum (UHV). It combines two complementary physical measurement principles in a single sensor head: a thermally compensated Pirani sensor for the rough and low vacuum range (1×10³ to 1×10⁻² mbar), and a cold cathode (Penning-type) discharge sensor for the high and ultra-high vacuum range (1×10⁻² to 1×10⁻⁸ mbar). This dual-sensor architecture eliminates the need for manual range switching or auxiliary gauges, enabling seamless, uninterrupted monitoring during vacuum system pump-down, process stabilization, and maintenance cycles. Designed and manufactured in Germany to stringent industrial quality standards, the PTR 90 delivers robust performance in demanding production and research environments—including semiconductor cleanrooms, vacuum metallurgy furnaces, and analytical instrument chambers—where long-term stability, contamination resistance, and electrical noise immunity are critical.
Key Features
- Dual-Principle Sensing: Integrated Pirani and cold cathode sensors ensure metrological continuity across 11 decades of pressure without hysteresis or calibration discontinuity.
- Contamination-Resistant Design: The cold cathode element operates without heated filaments, eliminating oxidation and deposition-related drift; the Pirani filament is shielded and thermally stabilized to reduce sensitivity to dust and hydrocarbon adsorption.
- Compact & Modular Integration: Stainless steel housing with KF 25 and CF 40 flange options enables direct mounting on vacuum chambers, feedthroughs, or manifold assemblies; minimal footprint supports space-constrained OEM integration.
- Flexible Signal Output: Standard digital communication via RS232 or RS485 (Modbus RTU protocol); optional analog outputs (0–10 V or 4–20 mA) support legacy PLC and SCADA systems.
- Adaptive Visual Feedback: Multi-segment LED bar graph with pulse-frequency modulation provides intuitive, real-time pressure indication—no external controller required for basic status monitoring.
- Industrial Environmental Rating: IP65 ingress protection ensures operational integrity in humid, dusty, or mildly corrosive ambient conditions typical of vacuum furnace control rooms and thin-film coating facilities.
Sample Compatibility & Compliance
The PTR 90 is compatible with inert, reactive, and mildly corrosive gas environments commonly encountered in vacuum processing—including N₂, Ar, O₂, H₂, and process gases such as SiH₄, NH₃, and CF₄. It is not intended for use with halogenated or strongly oxidizing vapors at elevated partial pressures. The gauge complies with EU Electromagnetic Compatibility Directive 2014/30/EU and Low Voltage Directive 2014/35/EU. Its design supports traceable calibration in accordance with ISO/IEC 17025-accredited laboratories. While the PTR 90 itself is not certified for SIL or ATEX applications, it is routinely deployed upstream of safety-critical interlocks in semiconductor CVD/PVD tools and vacuum heat treatment systems meeting SEMI S2, IEC 61508, and ISO 14644-1 Class 5–7 cleanroom requirements.
Software & Data Management
Leybold provides the free VacuGraph PC software suite for configuration, real-time data logging, and trend analysis. Via RS232/RS485, users can configure measurement units (mbar, Pa, Torr), set alarm thresholds, define averaging intervals (1–60 s), and export timestamped CSV files compliant with GLP audit trails. When integrated into larger vacuum system controllers (e.g., Leybold’s VARIO or TPU series), the PTR 90 supports synchronized multi-gauge acquisition, automatic range handover validation, and event-triggered data capture—enabling full compliance with FDA 21 CFR Part 11 requirements when paired with appropriate electronic signature and audit-log modules. No proprietary drivers are required; standard Windows COM port enumeration and Modbus register mapping simplify integration into LabVIEW, Python (PySerial), or MATLAB-based DAQ platforms.
Applications
- Semiconductor Manufacturing: Real-time chamber pressure monitoring during CVD, PVD, ion implantation, and etch processes—ensuring repeatable film stoichiometry, step coverage, and dopant activation profiles.
- Vacuum Coating & Deposition: Closed-loop control of optical, decorative, and functional coatings (e.g., TiN, DLC, AR/HR filters) where pressure directly influences adhesion, stress, and refractive index homogeneity.
- Heat Treatment & Sintering: Monitoring vacuum integrity in batch and continuous vacuum furnaces used for annealing, brazing, and ceramic sintering—preventing oxidation, decarburization, and pore entrapment.
- Analytical Instrumentation: UHV-compatible pressure verification in mass spectrometer source regions, electron microscope columns, and surface science UHV chambers (e.g., XPS, AES, LEED).
- R&D & Fundamental Physics: Supporting plasma physics experiments, atomic beam collimation, and quantum optics setups requiring stable base pressure and rapid pump-down characterization.
FAQ
Does the PTR 90 require periodic filament replacement like traditional hot-cathode gauges?
No—the cold cathode sensor operates without thermionic emission, and the Pirani filament is designed for >20,000 hours of continuous operation under nominal conditions. Neither element is user-replaceable; full sensor recalibration or factory service is recommended every 24 months for critical applications.
Can the PTR 90 be used in oxygen-rich or hydrogen atmospheres?
Yes, within its specified pressure range and gas compatibility limits. However, prolonged exposure to >10% O₂ above 10⁻² mbar may accelerate Pirani sensor aging; H₂ measurement is supported but exhibits slight positive deviation (~10–15%) due to thermal conductivity differences.
Is the PTR 90 suitable for bake-out procedures?
The sensor head is rated for continuous operation up to 80 °C ambient; for chamber bake-outs exceeding this temperature, thermal isolation (e.g., water-cooled extension tube or radiation shield) is required to maintain specified accuracy and longevity.
How is calibration traceability maintained?
Each PTR 90 ships with a factory calibration certificate referencing NIST-traceable primary standards. Field recalibration requires transfer to an accredited vacuum metrology lab using a capacitance manometer reference standard per ISO 3567 and ASTM E1973 guidelines.
What diagnostic functions are available via digital interface?
Modbus registers provide real-time sensor health flags—including Pirani open-circuit detection, cold cathode discharge failure, communication timeout, and internal temperature monitoring—enabling predictive maintenance and automated fault logging.
