Date: Thu, 26 Apr 2007 13:55:18 -0400
Reply-To: "Lazarski, Peter M." <Peter.Lazarski**At_Symbol_Here**US.NGRID.COM>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: "Lazarski, Peter M." <Peter.Lazarski**At_Symbol_Here**US.NGRID.COM>
Subject: Re: Speciality Calibration Gas source inquiry
In-Reply-To: A<773854B2E1C0D94687157C3B57F07FDC02DF6519**At_Symbol_Here**>

I would suggest contacting A2LA ( to learn of metrology labs in CA who could cal this device for your contractor. The information contained in this e-mail message and any attachments may be confidential. It is intended only for the use of the individual or entities named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by e-mail at the originating address. Peter Lazarski National Grid USA Lab. & Testing Svcs., Bldg. 1 7437 Henry Clay Blvd. Liverpool, NY 13088 (315)460-2114 -----Original Message----- From: DCHAS-L Discussion List [mailto:DCHAS-L**At_Symbol_Here**LIST.UVM.EDU] On Behalf Of Russell Vernon Sent: Thursday, April 26, 2007 12:46 PM To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU Subject: [DCHAS-L] Speciality Calibration Gas source inquiry Dear Fellow Chemists, In California we are being required to test some of our fume hoods with a tracer gas. We are also being encouraged to reduce our greenhouse gas emissions. The standard method, ASHRAE 110-1995, calls our sulfur hexafluoride as the tracer gas of choice. It takes about 0.5 to 1 kg of tracer gas for each test. SF6 has 23,900 times the global warming potential of CO2 largely dues to its stability and very long residence times in the atmosphere. ASHRAE 110-1995 allows for alternative tracer gases to be used but requires that they are similar in weight, stability and detection limits to SF6. The best alternative I've found so far is hexafluoropropene [116-15-4]. The current director of our Air Pollution Research Center ( ) assures me that hexafluoropropene will hang around in the atmosphere only 4-5 days so will not have the dramatic negative environmental impact of SF6 (also it will not deplete the stratospheric ozone). I have found a local fume hood certifier that is set up to conduct the ASHRAE 100-1995 test who is willing to try a new gas, but his detector is calibrated to SF6. We contacted the manufacturer of his Q200 leak detector and they need a certified calibration gas source. Normally they use a 1% mix of gas in nitrogen, and fill a 0.6 liter bottle with it to a pressure of between 4 and 10 bar. The set the leak rate of the gas at either 1 x 10-7 or 1 x 10-6 cc/sec, which corresponds to 0.1 and 0.2 ppm respectively. Can you recommend a lab, supplier or manufacturer that would be willing to create a certified mixture of 1% hexafluoropropene in nitrogen? (The manufacturer of the Q200 is in the UK so a European source may be the best.) Sincerely, -Russ Russell Vernon, Ph.D. UC System-wide Field Safety Working Group Chair Laboratory / Research Safety Specialist & Integrated Waste Manager Environmental Health & Safety University of California, Riverside 900 University Ave. Riverside, CA 92521 russell.vernon**At_Symbol_Here** Direct: (951) 827-5119 Admin: (951) 827-5528 Fax: (951) 827-5122 ******************************************************************************** This e-mail and any files transmitted with it, are confidential to National Grid and are intended solely for the use of the individual or entity to whom they are addressed. If you have received this e-mail in error, please reply to this message and let the sender know.

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