tegwin
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posted on 18/2/12 at 12:50 PM |
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Thermocouples
Anyone understand thermocouples?
I have this multimeter
HERE
It came with (what I assume) is a thermocouple. I have now lost it....
Any idea what type of thermocouple I can replace it with? I know there are varaious types J,k etc... but no idea which I need to order?!
Ideally I need a tiny tiny thermocouple for testing some electrical stuff....
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Madinventions
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posted on 18/2/12 at 01:01 PM |
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Give Rapid a quick call? They're open on Saturdays, and should be able to give you the information you need.
Ed.
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wylliezx9r
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posted on 18/2/12 at 01:16 PM |
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Thermocouples use 2 similar metals to produce a voltage when there's a change in temp. The metals also have to be matched by the wiring that
goes to the meter. So you are going to need the specific thermocouple for your meter or the read out will be incorrect. Best to contact
manufacturer.
ATH Dan
I spent a lot of money on booze, birds and fast cars. The rest I just squandered.
George Best
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Confused but excited.
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posted on 18/2/12 at 02:22 PM |
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quote: Originally posted by wylliezx9r
Thermocouples use 2 similar metals to produce a voltage when there's a change in temp. The metals also have to be matched by the wiring that
goes to the meter. So you are going to need the specific thermocouple for your meter or the read out will be incorrect. Best to contact
manufacturer.
ATH Dan
That would be two dissimilar metals, ie; iron/constantan for lower temp ranges, platinum/rhodium for higher ranges etc.
Tell them about the bent treacle edges!
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Marcus
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posted on 18/2/12 at 02:26 PM |
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The vast majority of these are k type. All the multimeters and temperature loggers at work use k type.
Marcus
Because kits are for girls!!
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tegwin
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posted on 18/2/12 at 02:30 PM |
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quote: Originally posted by Marcus
The vast majority of these are k type. All the multimeters and temperature loggers at work use k type.
That is the impression I am getting from my googling... Are all K type thermocouples the same? (appart from size) so I can just use any K type?
Rapids technical guys dont work at weekends, the people on today cant help me.
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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Paul_C
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posted on 18/2/12 at 03:10 PM |
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My understanding is that all K type thermocouples are the same. The K means that the junction is chromel / nickel according to Wikipedia.
There is at least one standard for the type of connector that uses the same material as the thermocouple because any dissimilar metal junction causes
some voltage which will change the reading. If it has one of those (available from RS Stock No. 455-9534 amongst others) then it's clear what
the multimeter uses.
I'm guessing that the standard multimeter terminals are used to connect the temperature sensor. If so it's possible that your meter came
with a thermistor which allows a cheaper internal circuit and possibly greater accuracy but with disadvantages as well. Unfortunately they
aren't standard.
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britishtrident
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posted on 18/2/12 at 03:57 PM |
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Easier to use one of these http://www.maplin.co.uk/handheld-non-contact-thermometer-590711
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
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tegwin
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posted on 18/2/12 at 03:58 PM |
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quote: Originally posted by britishtrident
Easier to use one of these http://www.maplin.co.uk/handheld-non-contact-thermometer-590711
I have something similar to that... But not suitable for this application. I need to glue a very small thermocouple onto a tiny pad on a circuitboard
and measure the temp in that specific area.... Should allow me to calculate junction temperatures. :-)
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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