Bed Temp 100 but IR said just 86!  

Re: Bed Temp 100 but IR said just 86!

The bed has zonal heating and IR thermometers can be quite inaccurate.

Peter

Re: Bed Temp 100 but IR said just 86!

I would think that the chepo thermistor connected with tape isn't that reliable.

Re: Bed Temp 100 but IR said just 86!

💡 even the cheap thermistors used at our i3 MK2/MK2S are quite accurate at this temperature range (error < 1°) !

➡ the thing with IR thermometers (precise would be: pyrometer or bolometer) is that all the surfaces you want to measure have different emmission intensity factors.
it should be obvious that a mirror plane steel surface has a different emmision intensity as wood or ceramics.

at cheap IR thermometers you can't adjust this value, so it's usually "set" to a value between 0.98 and 0.95. 🙄
at high-end pyrometers this factor is adjustable/selectable as well as at infrared cameras, depending on the type of surface you want to measure/monitor.

without adjusting this value the error for measuring the temperature of a surface with an IR thermometer is very large. i won't trust a common IR thermometer for exact measurements better than +/- 10% of their max. value.

by the way, i've already measured our MK42 printbed with an (quite expensive) infrared camera, where i had the chance to select the type of surface. you can have a look at the results here.

Re: Bed Temp 100 but IR said just 86!

I had the opposite problem just now, LCD temp reading 75c, and IR reads 116c! It turns out the thermistor got pulled out of the plastic pocket under the bed board.

Re: Bed Temp 100 but IR said just 86!

I had the opposite problem just now, LCD temp reading 75c, and IR reads 116c! It turns out the thermistor got pulled out of the plastic pocket under the bed board.

yes, quite a common issue. search the forum for "thermistor" and "loose", you'll find plenty reports about that.