Typically this force is 0.25 inches of h2o column, but can be lifted or decreased as the method requires. Isolators need to be periodically leak tested to be sure their integrity and prevent escape in the decontamination agent. Leak testing can be carried out by numerous procedures such as https://www.tumblr.com/tailinscitech/815206099011649536/why-choose-tailin-toc-analyzer-for-accurate-total?source=share