Guides & tutorial on temperature control needed

[Q]

Jul 8, 2015 17:14:23 GMT VapingBad said:

Jul 8, 2015 16:50:51 GMT letsavit said:

You can adjust the coefficient of resistance for different wire..as opposed to most being pre set for NI200...never used it and know no more.

Calling VapingBad as I think he has looked into more for the DNA200.

The Temperature Coefficient of Resistance (TCR) is the rate the resistance changes with temperature, normally a number for the proportion fo change per degree based at 20 C.  This is good enough for most wire, but some materials a single number is not accurate enough (I think this is due to expansion under heat also affecting the resistance).  With wires like stainless steel and titanium you need to be careful you have the right grade of alloy for your TCR as it varies a lot between grades.  In practical terms you would be fine with the right TCR for around the temp you vape at, but some mods like the Decodes and the DNA200 have more accurate way of doing it.  You can combine several wires and get a composite TCR on SteamEngine for the DNA200 so mixed wire fancy coils can be temp limited now.  The DNA uses a graph for TCR that you can edit in EScribe (DNA200 windows app), but it really meant for people selling wire to provide these that you can upload to your device. 

The DNA200 also has a diagnostic program to plot how your mod dissipates heat and I suggested a feature that will measure the mods resistance from the software when you short the 510 and John said "Not a bad idea am making a note of it".  The last time he said that to me the feature went in the beta fw the next day and went live 2 days later, so I am optimistic it will get in.  So the chip will be able to compensate for more things than just the TCR, if you buy a mod the maker should have set all this up before shipping so you don't need to do it unless you are making it yourself.

Well that explains it completely

It seems this one has an 'app' where you can gain further control ie the temp co-eff and adjust it


Bear in mind this is a first look at a pre-production model

[VapingBad]

It is just a rate Q like mpg or mg/ml, sorry not going to look at a half hour SMOK video and after their last attempt the best advise I can think of is wait for a lot of other people to get them first before spending your hard earned.

[Q]

Too late I've jumped in
The section on temp co-eff (which the reviewer doesn't understand) comes towards the end, and it is an unbiased review, not from Smok

[VapingBad]

Jul 8, 2015 17:42:23 GMT Q said:

Too late I've jumped in
The section on temp co-eff (which the reviewer doesn't understand) comes towards the end, and it is an unbiased review, not from Smok

about 17 mins, poor it is not set and as slider on a touch screen

You want for TCR
0.00641 for Ni
0.0033 for Ti (but have also seen different values like 0.0035 for "Titanium 1" so best to ask who you got your wire from)
0.00094 for SS 317L / Haywire (again ask the vendor as it can vary)

ETA
The TCR number is how much the resistance rises per degree Celsius above 20 C, EG at 200 C the temp has changed by 180 C so you would multiply the 20 C resistance by 180 * the TCR and add the result to the 20 c resistance.  If at 20 C or cold R = 0.5 ohm then 0.5*(200-20)*TCR+0.5 so for Ni 0.5*180*0.00641+0.5 = 1.0769 ohm @ 200 C
The higher the TCR number the more accurate the temp sensing will be, Kanthal and Nichrome have very very small TCR so no good with current tech for temp sensing.