Greetings all,

I find myself needing to do a more in depth ODH calculation primarily in regards to liquid nitrogen. I have a group that would like to put a second Dewar into a space that preliminary calculations puts the oxygen level at 13.28%. This does not take into account air exchanges for the room nor the fact that it is an active research/teaching instrumentation space. I need to be able to tell the researcher what their options are, but I have to do the math myself. There are other considerations to take into account for the room, but if the HVAC is the highest expense of the project, I would like to know that up front. I also have other compressed gases in the space, so I know that I am not getting the full picture.

Previously, this has not been a problem as our Departments have at most about 5 Dewars campus wide with none sharing. We are a smaller campus, but the research is growing.

I have been looking at Stanford’s page in regards to this to determine my numbers, but working out the next step calculations without a step by step process is making it difficult to determine.

Does anyone of a quick guide or an “Idiot’s Guide to Calculating your ODH value”?

Thank you for your assistance with this.

Margaret Smallbrock

Campus Environmental Health and Safety Manager

Environmental Health & Safety

South Dakota School of Mines

501 East St. Joseph Street

Rapid City, SD 57701-3995

605-394-6020

605-394-5837 FAX

Margaret.Smallbrock**At_Symbol_Here**sdsmt.edu