{"id":5243,"date":"2026-03-27T14:02:40","date_gmt":"2026-03-27T06:02:40","guid":{"rendered":"https:\/\/www.bacintl.com\/?p=5243"},"modified":"2026-03-27T08:38:54","modified_gmt":"2026-03-27T00:38:54","slug":"the-operation-principle-of-the-negative-pressure-weighing-chamber","status":"publish","type":"post","link":"https:\/\/www.bacintl.com\/ar\/the-operation-principle-of-the-negative-pressure-weighing-chamber\/","title":{"rendered":"The operation principle of the negative pressure weighing chamber"},"content":{"rendered":"<p>The core principle of the negative pressure weighing chamber is: through vertical unidirectional flow + local exhaust to form a stable negative pressure, locking dust \/ pollutants within the operation area and preventing them from leaking out, while ensuring the cleanliness of the operation area.<br \/>\nI. Core Structure (Key Components of Air Flow Path)<br \/>\nPrimary \/ Intermediate Filter: Pre-filters large particles to protect the fan and the high-efficiency filter.<br \/>\nCentrifugal Fan: Provides power to drive the air circulation and exhaust.<br \/>\nHigh Efficiency Filter (HEPA): Captures particles of 0.3\u03bcm with a retention rate of \u2265 99.99%, ensuring the cleanliness of the supply air.<br \/>\nEqualizing Mesh \/ Equalizing Membrane: Forms a uniform vertical laminar flow (about 0.45m\/s).<br \/>\nReturn \/ Exhaust System: Collects the dust-containing air flow, partially recycles and partially discharges.<br \/>\nPressure Difference Control System: Maintains a relative negative pressure of the operation area to the external environment (usually -15~-30Pa).<br \/>\nII. Operating Process (Air Flow and Negative Pressure Formation)<br \/>\nReturn Air Purification<br \/>\nDust-containing air in the operation area enters through the bottom return mesh, and passes through the primary \/ intermediate filters successively to remove large particles.<br \/>\nSupply Air Purification<br \/>\nThe purified air is sent by the fan into the high-efficiency filter to achieve ISO 5 cleanliness.<br \/>\nAir Flow Distribution (Key)<br \/>\nApproximately 90% of the clean air: Forms a vertical unidirectional flow through the equalizing mesh, covering the operation area downward, and carrying the dust back to the return area.<br \/>\nApproximately 10% of the clean air: Directly discharged outside the equipment.<br \/>\nNegative Pressure Formation<br \/>\nBecause the exhaust volume is greater than the return volume, the air pressure in the operation area is lower than the external environment, forming a stable negative pressure, and the air flow can only flow from outside to inside, completely preventing the dust from leaking out.<br \/>\nCirculation and Monitoring<br \/>\nDust-containing air flow is continuously filtered, purified, and sent back for circulation, forming a closed loop; pressure difference \/ wind speed sensors monitor in real time, and issue alarms for abnormalities.<br \/>\nIII. Core Function<br \/>\nPrevent Leakage: Negative pressure + vertical flow dual locking of dust, protecting personnel and the environment.<br \/>\nPrevent Cross-Contamination: Mainly self-circulation, without affecting the overall pressure difference of the room.<br \/>\nClean Operation: Meets the cleanliness and safety requirements of GMP\/ISO for the weighing of highly active and highly toxic materials.<\/p>","protected":false},"excerpt":{"rendered":"<p>The core principle of the negative pressure weighing chamber is: through vertical unidirectional flow + local exhaust to form a stable negative pressure, locking dust \/ pollutants within the operation area and preventing them from leaking out, while ensuring the cleanliness of the operation area. I. Core Structure (Key Components of Air Flow Path) Primary [&hellip;]<\/p>","protected":false},"author":3,"featured_media":5246,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[92],"tags":[],"class_list":["post-5243","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/5243","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/comments?post=5243"}],"version-history":[{"count":1,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/5243\/revisions"}],"predecessor-version":[{"id":5247,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/posts\/5243\/revisions\/5247"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/media\/5246"}],"wp:attachment":[{"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/media?parent=5243"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/categories?post=5243"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bacintl.com\/ar\/wp-json\/wp\/v2\/tags?post=5243"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}