The standard specifications for a vacuum gauge with a mild steel (MS) casing, brass internals/connection, 3/8“ BSP bottom entry, and typical commercial design include a -760 to 0 mmHg range, 4-inch (100 mm) dial, and ±2% full-scale accuracy. Dial Size: Usually 4 inches (100 mm) or 6 inches (150 mm)Measurement Range: -760 mmHg to 0 (with dual scale -30 inHg to 0)Casing Material: Powder-coated Mild Steel (MS), usually black anti-corrosive finish Wetted Parts & Internals: Brass (Bourdon tube and movement)Process Connection: 3/8” BSP Male (British Standard Pipe), bottom-mounted entry Accuracy Class: ±1.6% to ±2.0% of Full Scale Deflection (FSD)Mounting Type: Direct bottom mounting or 3-hole surface/wall mounting Compliance Standards: Manufactured generally in accordance with EN 837-1 benchmarks