Nozzle temperature

[timskloss]

After assembling my V3 I set out to calibrate the HE280 thermistor, but how to read the temperature of the nozzle easily?

Well, if you are like me and have tons of hobbies, you may have collected a ton of thermocouples. I collect K-type thermocouples and have a few meters around that help me: smoke the perfect brisket, trouble shoot appliances, maintain my aquarium, etc.

But this one was perfect for the job: http://www.omega.com/pptst/HJMTSS.html

I have the 0.020" (0.5 mm) one in 12" length. To measure the nozzle temperature I removed the Bowden tube and inserted the TC from the top down into HE280. See picture. I coiled the TC near the handle to act as a strain relief. These are fragile thermocouples. You have to gently fiddle with the TC to get it all the way down to the nozzle, but once there gravity will keep it in contact with the nozzle. Depending upon the tolerances of your nozzle and the TC it may or may not go through the nozzle. Ideally you want the tip of the TC right in the nozzle hole, or touching the back side of it.

[img]https://c7.staticflickr.com/6/5608/30904176886_efe99d7c9c.jpg[/img]

My HE280 was reading 8-10 degrees cooler than the actual temperature. A quick fix to the beta value dialed it right in. HINT: Take the temperature you set and divide by the actual temperature to get a correction ratio. Multiply the ratio by your existing beta value to get the new beta value. Worked perfectly.