CLASS B CLASS H CLASS S CLASS K Seal (fine and gross leak) MIL-STD-883, method 1014: Fine Leak: A 1, A 2, or B (A 1, A 2: tracer gas helium, flexible method. B: Radioisotope) or MIL-STD-202, method 112 test condition C (tracer gas, nominal leak value 10-8 atm. cm3/s, proc 3: force gas in, or proc 4: backfill). Gross Leak: perfluorocarbon or