4. Open valve (E) slowly to maintain a pressure of 10.0 inches H₂O throughout the system as indicated on manometer (4). Close valve (E). Any further climb on manometer (4) indicates a leak through valve (H). 5. Open valve (E) to maintain 20.0 in. H₂O. When pressure is constant, observe rotameter (8). There should be no leakage. 6. Turn valve (F) to LOW RANGE. The rotameter (7) should indicate no leakage. 7. Return valve (F) to HIGH RANGE, and close valve (E). Remove the hose from connec- tion (19) and allow the pressure to escape from the hose. NOTE: Open valve (C) to aid in relieving pressure; then close it. 8. When the pressure has equalized, connect the hose from tap (21 ) to tap (20) in the chamber. Rotameter (6) should show no indication of leakage. 9. Remove the cap from Piezometer (26), and disconnect the hose between taps (20) and (21) in the chamber. 10. Turn the regulator (N) counterclockwise, and open valve (S) to bleed system. Close all test stand valves with the exception of valves (R) and (J). Altitude Chamber and Suit Simulator Tank Inward Leakage Test Perform the altitude chamber and suit simulator tank inward leakage test as follows: 1. Place valve (D) in the Hg position. Ensure the ON/OFF valves (G) and (L) are in the OFF position. Place valve (0) in the suit simulator position. 2. Close the chamber door and turn the vacuum pump motor ON. 3. Open the VACUUM CONTROL valve (B₁) and “ascend” to 30,000 feet. Close (B₁) and check to ensure that the same altitude is indicated on both altimeters (12) and (13). At 30,000 feet you will see the high-range altimeter start to climb and at 40,000 feet the low-range altimeter will no longer be in use. This happens automatically and the low-range altimeter will not be damaged. 4. Using valve (B₁) “ascend” to 40,000 feet; ensure that altimeters (12) and (13) register the same altitude. 11-12 5. Using the VACUUM CONTROL valve (B₁), ascend to 52,000 feet. (Altitude is indicated on altimeter (12).) 6. Close (B₁); after a 2-minute stabilization period, record the altitude indicated on altimeter (12). Altitude “loss” should not exceed 1000 feet in 20 minutes. PERIODIC INSPECTIONS Periodic inspections consist of daily, weekly, biweekly, and monthly inspections. Perform these inspections at the prescribed intervals using the procedures described in the following text. Daily Inspection Perform the daily inspection as follows: 1. Check the vacuum pump lubricant for the proper level (run the pump for 2 minutes and recheck for proper level). 2. Inspect the gauges and manometers for cleanliness, fogged or broken glass, and zero or normal indications. 3. Inspect the altitude chamber door for cleanliness, chips, scratches or cracks. Check the gaskets for excessive wear or deterioration. 4. Inspect the connections and adapters for cleanliness and distortion. 5. Check the identification plates for cleanliness, legibility, and security of attachments. Weekly Inspection The weekly inspection includes all the tasks of the daily inspection and the following addi- tional tasks: 1. Inspect the polyethylene tubing, fittings, connections, and rubber couplings for the correct fit, dirt or excessive dust, pin holes, radical bends or kinks, surface abrasions and heat blisters. 2. Inspect the gauges, manometers, and flowmeters for the correct calibration decals, proper fluid level, and cleanliness of manometer and flowmeter tubes. 3. Perform the pressure leakage tests in accordance with NAVAIR 13-1-6.4.