Advanced Dehydration | Module 115
Vacuum Dehydration Audit
Field Status: A “stalling” micron gauge can be deceptive. A leak results in a continuous pressure rise, while moisture off-gassing results in a “leveling off” as the moisture reaches equilibrium with the vacuum.
Use this diagnostic terminal to interpret your decay test. Input starting and ending vacuum levels to differentiate between a leak and residual moisture.
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Vapor Pressure & Equilibrium
Under a deep vacuum, moisture exists as liquid but attempts to reach equilibrium with the low-pressure environment by evaporating. This phase change adds vapor pressure to the system, causing the micron gauge to “stall” or rise until the system stabilizes. The efficiency of the system depends entirely on the technician’s ability to maintain a deep vacuum until all latent moisture has phase-shifted.
| Rise (Microns/Min) | Diagnosis | Action |
|---|---|---|
| < 50 | Dehydrated | Charge System. |
| 50 – 300 | Moisture | Continue Vacuum. |
| > 300 | Leak | Perform Leak Test. |
Diagnostic Gateway Challenge
Why does moisture in a vacuum stall the micron gauge?