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EE in Training
Aug 26, 2008, 10:38 AM
Hi I am new to this but I am in need of assistance. I have a circuit that I am developing to test a change in air Temperature of 500 degrees F. Ive already decided to use a K type Thermocouple from omega products, Ive also decided on using a break wire but can't truly find specs on the wire ( i.e.. Melting point, thickness... ). I am looking for a third device that is compatible with omega and NI's Labview systems. Ive also considered RTDs but they have a slow response time and thermistors won't survive the test. If anyone is fimilar with restrained firing test or have worked with devices that measure temperature behind rocket motors please reply. Thank you

KISS
Aug 26, 2008, 01:12 PM
Totally confused:

500 degrees F. Who uses F these days? Change from what to what?
Sheath material, isotation, more than one TC, Grounded, ungrounded,
Conditioning, how fast of a response are all going to matter.

You got me. I have no idea what a break wire does. What does it do?

What's your mysterious "third device" need to do?

EE in Training
Aug 26, 2008, 01:48 PM
Totally confused:

500 degrees F. Who uses F these days? Change from what to what?
Sheath material, isotation, more than one TC, Grounded, ungrounded,
Conditioning, how fast of a response are all going to matter.

You got me. I have no idea what a break wire does. What does it do?

What's your mysterious "third device" need to do?


All right all right 260 degrees C.
Ambient to 260 or just a dramatic change in temperature.
Sheath material and Grounded, Omega cold junction compensater.
Test last 60sec must response in milsec.
A break wire is a thin wire that breaks easily, but I've decided to cut the wire anyway and soder it so it will have a faster response time.

Detect fire, change in IR, or thermal detection

I hope this helps thanks

DrLang
Aug 27, 2008, 05:09 PM
Why won't the thermocouple work? Is it not fast enough? Pretty much anything is compatible with LabVIEW so long as the signal is conditioned for a DAQ card. Have you considered just using a thin piece of solder with a small current running through it to indicate that it is still in tact?

EE in Training
Aug 28, 2008, 04:24 AM
Why won't the thermocouple work? Is it not fast enough? Pretty much anything is compatible with LabVIEW so long as the signal is conditioned for a DAQ card. Have you considered just using a thin piece of solder with a small current running through it to indicate that it is still in tact?


I am going to use a K type thermocouple and a break wire that's connected with solder. I am truly looking for a third device to test the system and I am leaning more to a thermal fuse. Have you heard or used one of these before (ie. Thermal fuse)?