A 12-inch wafer fabrication facility requires maintaining a micro-differential pressure of 5–10 Pa in cleanroom zones 1–3 to prevent cross-contamination. Acid and alkali exhaust gas systems operate under highly corrosive, high-negative-pressure conditions.

• Extremely high precision required for micro-differential pressure (5 Pa), making conventional instruments unstable;
• Strong corrosion from acid and alkali exhaust gases, leading to diaphragm perforation and leakage;
• Large fluctuations in duct negative pressure, causing frequent fan surge and alarms.

• Deltabar PMD75B differential pressure transmitter (for cleanroom micro-pressure control, accuracy ±0.035%);
• Cerabar PMP55B (with Hastelloy C276 material) (for acid and alkali exhaust gas applications).

• Cleanroom micro-differential pressure maintained within ±1 Pa, with zero cross-contamination incidents throughout the year;
• Hastelloy C276 diaphragms showed no corrosion after 18 months of continuous operation in pH 1–14 exhaust environments;
• Stable data output within ±10 Pa, automatic alarm triggered above 50 Pa, eliminating fan surge and shutdowns;
• A total of 4,200 units deployed across the project, establishing a benchmark in China's semiconductor industry.