Testing Hotend with External Thermocoupler

[cassetti]

I forget where I read it, but I remember some people recommended the Extech Instruments MN35 Multimeter for it's relatively accurate thermocoupler. I brought a pot of water to a boil and confirmed it was within 3 degrees of 100C (it was hard to take the picture, thermocoupler was out of water by time picture was snapped).
[img]https://sphotos-a.xx.fbcdn.net/hphotos- ... 6703_n.jpg[/img]

One problem though, where the heck do I place the thermocoupler to get the best reading on the hotend? I'm reading 180C max when I'm setting Repetier to 230. Now I know that must be wrong, because there'd be no way in hell I'd be printing as successfully with ABS as I am if it were really running at 180C. And when I test at 190C, I get 160C.

I know my bed temps will be off by a few degrees because the thermistor is buried under an Aluminum Plate and Borosilicite glass, but I should be able to get close with the hotend!

Hotend Fan was off throughout testing

[cambo3d]

I tested mine inside the nozzle before I feed any filament through it. I found that testing it from the outside gave me inaccurate nozzle readings and was nowhere near the set temperature.
measuring outside of nozzle http://forum.seemecnc.com/viewtopic.php ... =140#p7612 not so accurate

measuring inside of the nozzle http://forum.seemecnc.com/viewtopic.php ... =150#p7740 more accurate

those yellow wires you see at top and the bottom are my two thermocouple sensors.

[cassetti]

Ah Hah! Gotcha, I'll give that a shot if I get time today, it's a holiday after all

[foshon]

Ah Hah! Gotcha, I'll give that a shot if I get time today, it's a holiday after all

+1 (if my job would let me)

You'll have to pull the ptfe tube out to fit that in the hole.