BAG402 is a Bayard-Alpert hot cathode ion vacuum gauge. It uses two yttria coated iridium filaments, its sensor carrying calibration data can be swapped, and it measures base pressure in semiconductor process and transfer chambers.
| Measuring Range | 5×10⁻¹⁰ … 2.7×10⁻² mbar (3.75×10⁻¹⁰ … 2×10⁻² Torr) |
| Accuracy | ±15% of reading |
| Supply Voltage | +20…+28 / ≤0.8 V/A (dc) |
| Operating Temperature (in operation) | 0…+50°C |
| Filament | Two Yt2O3 coated Ir |
| Bakeout | Flange 80°C (electronics removed) |
| Repeatability | 5% (of reading, 10⁻⁸…10⁻² mbar) |
| Maximum Pressure (absolute) | 2 bar |
| Interface | Diagnostic port RS232C |
| Storage Temperature | -20…+70°C |