BCG450 Vacuum Gauge System – INFICON Combined Bayard-Alpert Ionization, Convection-Enhanced Pirani, and Capacitance Manometer Sensor

Overview

The INFICON BCG450 is a fully integrated, multi-principle vacuum measurement system engineered for high-reliability operation across an exceptionally wide pressure range—from 5 × 10⁻¹⁰ mbar (3.75 × 10⁻¹⁰ Torr) up to 1500 mbar (1125 Torr). Unlike conventional single-sensor gauges, the BCG450 combines three distinct vacuum sensing technologies within a single compact housing: a Bayard-Alpert (B-A) hot-cathode ionization gauge for ultra-high vacuum (UHV), a convection-enhanced Pirani sensor for low-to-medium vacuum, and a capacitance manometer for accurate absolute and differential pressure measurement in the rough and high vacuum regimes. This hybrid architecture eliminates the need for separate gauge installations, reducing mechanical footprint, cabling complexity, and calibration overhead—while maintaining traceable, gas-independent readings above 10 Torr and enabling robust process interlocks in semiconductor and thin-film manufacturing environments.

Key Features

• Triple-sensor integration: B-A ionization gauge (5 × 10⁻¹⁰–1 × 10⁻³ mbar), convection-enhanced Pirani (1 × 10⁻³–1000 mbar), and sealed-diaphragm capacitance manometer (0.1–1500 mbar)
• Gas-type independence above 10 Torr enabled by capacitance manometer reference mode and automatic Pirani atmospheric compensation
• Pirani filament protection logic: real-time thermal overload detection prevents premature burnout during accidental atmospheric exposure or rapid pressure transients
• Self-calibrating Pirani operation: automatic zeroing and span adjustment at atmospheric pressure and high vacuum endpoints—no manual intervention required
• Differential pressure capability: referenced to ambient barometric pressure via internal temperature-compensated barosensor, eliminating drift caused by weather-related atmospheric fluctuations
• Modular sensor head design: field-replaceable sensing elements with embedded EEPROM storing NIST-traceable calibration coefficients—ensuring measurement reproducibility after replacement
• Optional accessories: integrated graphical display module (LCD with real-time trend logging) and industrial fieldbus interfaces including Profibus DP, DeviceNet, and EtherCAT

Sample Compatibility & Compliance

The BCG450 is compatible with inert, reactive, and corrosive process gases commonly encountered in vacuum deposition, etching, and analytical instrumentation—including Ar, N₂, O₂, CF₄, SF₆, and H₂. Its stainless-steel sensor housing and ceramic insulators meet ISO 10110 optical surface standards for UHV cleanliness. The system complies with IEC 61000-6-2 (EMC immunity) and IEC 61000-6-4 (EMC emissions), and supports GLP/GMP audit trails when paired with INFICON’s VACUUBRAND VACUUBUS software suite. While not certified as intrinsically safe, the BCG450 meets UL 61010-1 requirements for laboratory electrical safety and is designed for use in Class 1, Division 2 hazardous locations per NEC Article 500 when installed with appropriate barrier systems.

Software & Data Management

The BCG450 communicates via RS-485 (Modbus RTU) or optional fieldbus protocols, enabling seamless integration into SCADA, MES, and PLC-based control architectures. INFICON’s VACUUBUS software provides full configuration, real-time data visualization, alarm management, and automated log export in CSV or XML formats. All measurement events—including sensor switchovers, auto-zero cycles, and filament activation—are timestamped and stored with operator ID and system status metadata. When configured with FDA 21 CFR Part 11-compliant authentication modules, the system supports electronic signatures, audit trail generation, and role-based access control—meeting stringent regulatory requirements for pharmaceutical and medical device manufacturing validation.

Applications

• Semiconductor front-end processing: chamber pressure monitoring during CVD, PVD, ALD, and plasma etch steps—enabling closed-loop endpoint detection and recipe-driven pressure ramping
• Optical and decorative coating lines: real-time control of base pressure and process pressure in multi-chamber sputtering and evaporation systems
• Research-grade UHV systems: load-lock and transfer chamber monitoring where long-term stability and cross-range continuity are critical
• Accelerator and synchrotron beamline instrumentation: differential pressure measurement across gate valves and pumping stages under varying ambient conditions
• Leak detection support: serving as a stable reference gauge during helium mass spectrometer leak testing sequences

FAQ

Does the BCG450 require periodic recalibration?
No routine recalibration is needed—the embedded calibration data is retained in non-volatile memory, and the system performs self-validation during each power-up cycle. However, annual verification against a NIST-traceable reference standard is recommended for ISO/IEC 17025-accredited laboratories.
Can the BCG450 measure differential pressure across a valve or filter?
Yes—when configured in differential mode, it measures pressure difference relative to ambient using its internal barosensor, making it suitable for monitoring filter clogging or valve integrity without external reference lines.
Is the B-A ionization gauge filament susceptible to hydrocarbon poisoning?
The BCG450 employs a dual-filament design with automatic filament switching and emission current limiting, significantly extending operational life in hydrocarbon-rich environments. Optional bake-out compatibility (up to 150 °C) further mitigates contamination accumulation.
What is the maximum cable length between the sensor head and controller?
For RS-485 communication, the maximum recommended distance is 1000 meters using shielded twisted-pair cable meeting TIA/EIA-485-A specifications; fieldbus variants follow respective protocol distance limits (e.g., 100 m for Profibus DP at 12 Mbps).