ASOLO any wire TC mod will be on JOHN BOLD for appr £70 shpd

[phatfil]

just thinking aloud.. but as type K thermocouples are made extensivly out of hi concetrations of nickel alloy why not make a thermocouple coil??
en.wikipedia.org/wiki/Alumel (95% nickel, 2%manganese 2% alluminium, 1% silicon)
en.wikipedia.org/wiki/Chromel (90%nickel 10 % chromium)

would a twisted wire coil terminated with single strand legs be able to provide both a vapable coil AND a valid real time temperature reading too??

i suspect when using electronic circuits and components like resistors with a % of accuracy to infer an analoge value , all those %'s can accumulate to a significant drift without acccounting for less than perfect solder and mechanical electrical connections in a circuit which i suspect could be the reason for some of the inaccurate TC/TL mods that have emerged..

[VapingBad]

Sept 8, 2015 1:18:01 GMT phatfil said:

just thinking aloud.. but as type K thermocouples are made extensivly out of hi concetrations of nickel alloy why not make a thermocouple coil??
en.wikipedia.org/wiki/Alumel (95% nickel, 2%manganese 2% alluminium, 1% silicon)
en.wikipedia.org/wiki/Chromel (90%nickel 10 % chromium)

would a twisted wire coil terminated with single strand legs be able to provide both a vapable coil AND a valid real time temperature reading too??

i suspect when using electronic circuits and components like resistors with a % of accuracy to infer an analoge value , all those %'s can accumulate to a significant drift without acccounting for less than perfect solder and mechanical electrical connections in a circuit which i suspect could be the reason for some of the inaccurate TC/TL mods that have emerged..

On the face of it Thermocouple coils sound good, but would be need extra connections and no doubt people would start posting how they would poison you.   Ni200 can give you a accurate and consistent reading, is cheap, easy to make coils with and readily available, but evermore important IMO is it is always reading the part(s) that get hottest.

Discrete component accuracies are better than they used to be and you can design around the the accuracy for a lot of the circuit, but they still matter in key areas as do all the other things you list.  And as you say these will make a mod perform poorly, I know the DNA40 suffered form some of the 510 connections being inconsistent and effecting the refinement mode and the heat produced by wireless charging could do the same.  I think that consistency is more important than accuracy or to put it another way the accuracy is wasted on an inconsistent device.   So you need to make your production vary consistent, design in the ability to calibrate the device and have smarter firmware.  It is happening quite a few designs have a resistance offset now, the DNA200 takes it way farther and you can test the case cooling & heating time constants and heat the board picks up from battery charging (mod makers should do this and load the results on every device) and all this is used in refinement mode to be able to get a more accurate baseline for your coil.

[phatfil]

IM out of my depth with the electronics, But If atty posts. 510 connectors and the wiring to the evaluating circuitry are also made from the thermocouple metals then no other components should be necessary?

thermocouple poisoning ???? quite possibly, again im out of my depth again...

Ni200 can give you a accurate and consistent reading, is cheap, easy to make coils with and readily available, but evermore important IMO is it is always reading the part(s) that get hottest.

Im still treading water uncomfortably, But is it?? Shirley the coil metrics still dictate its resistance and unless the coil is heated up evenly and the whole body is heated to the same temperature its resistance change due to heat will also be uneven along its length i think a circumstance of 10% of the coil hitting 250C with the remaining 90% of it remaining at a lower 100C temp would provide the same resistance change as if the whole coil was heated evenly to something like 120C??

with a hotspot in the coil its resistance would be the same as 3 resistors in serial (R1(pre hot spot resistance) + R2(hot spot resistance) and + R3(Post hotspot resistance)

[VapingBad]

The coils dimensions and resistance don't matter phatfil it is just the % change in resistance of the coil that is required. The change in R with temp is a physical property, size also changes a little and that will affect R, not significantly with Ni though. EG I checked a couple of meat thermometers for my bbq by putting them in boiling water to see if they read 100 C as that is a physical property of H₂O regardless of how much water or the size or shape of the pan, in the same way that Ni change resistance predictably regardless of size.

It is the mean average temp for the coil including legs and will be affected by hot-spots and you can still get them. You are right it wont heat perfectly evenly any more than other coil materials, but measuring the coil R for temp will include the whole coil or coils which would be impossible in a one size fits all solution to work with any atty.



I have no idea about poising form thermocouples either, but have read loads of BS about Nickel being bad.

[phatfil]

Cheers VB.. Im slowly getting a grip on this ....