Stanford Research RGA100

The Stanford Research Systems RGA100 is a residual gas analyzer for real-time vacuum chamber composition monitoring and analysis. It identifies leaks, contaminants, and process-related gases across a 1–100 amu mass range with sub-amu resolution and detection limits as low as 5 × 10⁻¹⁴ Torr (with electron multiplier). The instrument captures six orders of magnitude dynamic range in a single scan, enabling simultaneous measurement of trace and bulk gas species.

A temperature-compensated logarithmic electrometer detects ion currents from 10⁻¹⁵ to 10⁻⁷ amps with better than 2% precision. The dual thoriated-iridium filament is user-replaceable and includes firmware-driven overpressure protection. Faraday cup and optional electron multiplier detectors accommodate both standard and ultrahigh-sensitivity applications.

RS-232 and optional Ethernet interfaces support integration into automated vacuum control systems.

Technical Specifications

• Mass range: 1–100 amu


• Resolution: Better than 1 amu; better than 0.5 amu at 10% peak height (AVS std. 2.3); adjustable constant peak width across mass range


• Detection limit (Faraday cup): 5 × 10⁻¹¹ Torr


• Detection limit (electron multiplier, optional): 5 × 10⁻¹⁴ Torr


• Dynamic range: Six orders of magnitude per scan; ion current detection from 10⁻¹⁵ to 10⁻⁷ amps at better than 2% precision


• Sensitivity (Faraday cup): 2 × 10⁻⁴ A/Torr (N₂ at 28 amu, 70 eV electron energy, 12 eV ion energy, 1 mA emission current)


• Sensitivity (electron multiplier): <200 A/Torr (user adjustable)


• Ionizer: Open ion source with cylindrical symmetry; electron impact ionization; built-in degassing via electron impact desorption


• Power supply: External +24 VDC at 2.5 A via DB9 connector; optional AC module (110/120/220/240 VAC)


• Probe flange: Standard 2.75" ConFlat (CF)


• Probe length: 8.75" from flange face; requires 2.5" internal clearance


• Minimum tube ID: 1.375"


• ECU dimensions: 3.1" × 4.1" × 9.1" (separable for high-temperature bakeout)


• Weight: 6 lbs

Key Features

• Dual thoriated-iridium filament with field-replaceable design


• Firmware-driven filament protection with overpressure shutdown


• Stainless steel probe with self-aligning components for rapid reassembly


• Optional electron multiplier for trace-level analysis


• Logarithmic electrometer for single-scan dynamic range capture

Interfaces & Integration

• Standard RS-232 with high-level command set for program integration


• Optional Ethernet connectivity


• Detachable electronics control unit for independent vacuum system operation