I agree with you. If an agency disallows a particular test set-up or procedure, they should be able to articulate that concern in writing and justify it as well. I know that may sound somewhat idealistic. Ralph McDiarmid, AScT Compliance Engineering Group Xantrex Technology Inc. www.xantrex.com
From: Stone, Richard A (Richard) [mailto:rsto...@lucent.com] Sent: April 28, 2003 2:02 PM To: 'Ralph McDiarmid'; emc-p...@majordomo.ieee.org Subject: RE: Thermocouple glue I don't agree with the general approach and opinions on traditional yeah vs. nay....just because they ( Safety Agency) doesn't understand, if the Mfr'r uses it in the right context, and it does not promote a safety deviaition than it should be accepted... a concrete reasoning for NOT accepting it should be pushed for and confirmed by looking at the safety standard being used... one man's opinion again: Richard, From: Ralph McDiarmid [mailto:ralph.mcdiar...@xantrex.com] Sent: Monday, April 28, 2003 4:45 PM To: emc-p...@majordomo.ieee.org Subject: RE: Thermocouple glue If it can be shown that the thermocouple remains attached and in good contact with the surface to be measured, I don't know why the agencies would not accept the use of thermal grease. There concern might be the affect the thermal compound has on the adhesive of the tape. Sometimes, they oppose things they simply don't understand or have no experience with. Fair enough, I suppose, I can see their point of view and they must take a conservative approach at all times. Ralph McDiarmid, AScT Compliance Engineering Group Xantrex Technology Inc. www.xantrex.com From: Brian O'Connell [mailto:boconn...@t-yuden.com] Sent: April 28, 2003 9:55 AM To: emc-p...@majordomo.ieee.org Subject: RE: Thermocouple glue My use of thermal grease was discontinued several years ago by request of various agency engineers reviewing test data/technique. And more recently, during my ISO 17025 audit, the NCB auditor explicitly directed me to never use thermal grease for thermocouple application. And auditors from other NRTLs/NCBs have emphasized, at least verbally, that thermal grease is not acceptable. R/S, Brian -----Original Message----- From: Ron Pickard [ mailto:rpick...@hypercom.com] Sent: Friday, April 25, 2003 10:19 AM To: emc-p...@majordomo.ieee.org Subject: Re: Thermocouple glue To all, I'm surprised that no one hasn't mentioned this yet. In the past for this application, the securement that I was introduced to was fiberglass tape and that white thermal grease. The tape exhibited high thermal stability and was used to secure the thermocouples, but left adhesive residue when removed after a temperature test. The thermocouple was inserted into the grease which offered excellent thermal conduction from the measurement point to the thermocouple. The downside to this grease, as anyone who's used this grease would say, is that the grease is "messy to the extreme" and it generally could not be completely removed from any surface that it came in contact with. And, it always found a way to get onto unintended surfaces including clothing. But, as a plus, the thermal grease would stay put physically over a very wide temperature range.
