Welder Preheat etc temp measuring !

Date 02-28-2015 15:49

Ladies and Gentlemen,
Played with temperature measuring like water pistol gismo that was about 100 bucks according one that lent it to me for preheat checking. Went to Home Depot® got one for thirty. Friend says temp sticks for welders and get the 500 or 1000 dollar one. Want your views on the less expensive electronic heat measuring gismo's , whether it is good tool for welders and as CWI ( inspector ) , engineer which one to use if at all. Greatly appreciate input. Personal will being using as CWI - Engineer.
Sincerely
Len Andersen 914-536-7101 // 800-4284801
By the by Verizon is running on my telephone lines pursuant to complaint given them from Washington FCC !
Input appreciated. len@spemail.org email best current my one of twenty years weld@spemail hacked out
sort of alive !

By 803056

Date 02-28-2015 16:09

I have used several different infrared thermometers. They all work, but many of the low cost machines are not adjustable and cannot be corrected for different emissivity.

I always check a test surface with both a thermocouple and the infrared thermometer to verify the infrared is reading accurately enough for the application.

Best regards - Al

By welderbrent (*****)

Date 02-28-2015 16:21

Len,

As per Al's comment, I have several, even the cheap ones work, but how accurately is the question. My 'Fluke' is about $300 if I remember correctly but it can be calibrated. And, one needs to check it against different surfaces with either a thermocouple style or temp sticks. (Oh, don't you mean 500 and 1000° temp sticks, not 'dollars'; I've never seen temp sticks that expensive.)

Cheap ones are good for welders but they need to make certain they are at least close to accurate and take their parts to a higher heat anyway because by the time they shut down the torch and get ready to weld the part isn't warm enough anymore anyway. Too many want to get just barely warm enough, and not in the through thickness, and then by the time they actually strike an arc their part is WAY below the specified pre-heat.

I use the infra red indicators as an estimate and if I want to challenge the shop I pull out my temp sticks of which I have: 100°, 150°, 225°, 250°, and more including 500°, 550°, and 1000°. Need to have one that is at least close to the pre-heat their WPS, the applicable code, and/or the Contract Documents call for.

He Is In Control, Have a Great Day, Brent

By Len Andersen (***)

Date 03-03-2015 19:41

Thank you ! Where I seen advantage for the 30 dollar one was fast preheat check as a CWI on D1.1 work. It allowed me to be a meter away and not interfere with the welder ready to strike arc. It was not so precise. Often in D1.1 the preheat does not happen if you are not standing there.