| 摘要 |
<p>1. A control group comprising an ammonia gas source (19) for testing the tightness of a closed container (1), using for the purpose of detecting possible leakages the change of a coloured agent when put into contact with the gazeous ammonia, which, put under pressure, fills the formerly evacuated container, characterized in that it operates automatically and further comprises a vacuum pump (11) compatible with the ammonia and a source of flush gas connected to said container by ducts (4, 8, 10), and at least one detector (35) operating at a pressure lower than atmospheric pressure and at least one detector (36, 37, 39) operating at a pressure higher than atmospheric pressure mounted directly on the container (1) and connected with threshold detector circuits (45 to 49) specifically adjusted to the cycles of filling in pressurized ammonia, draining the ammonia and flushing the container, and wherein said ducts (4, 8, 10) are subdivided by an electric valve (5, 12, 26, 14) directly controlled by the threshold detector circuits related to the respective cycles.</p> |
