Room Temperature bug

[labo]

Hi,
I have a Vt200, I noticed that room temperature reading is always wrong.
Right now room temperature is 62,6 °F, I'm sure the box has the same temperature, it's been 2 hours that I'm not using it.

When I attach it to Escribe to monitor the Temp I can see that the board temp is fluctuating (it raises when I hold it in my hand), the room temp instead is always the same (73,88 °F)

So there must be a problem and ohm analyzer can't correct ohm reading @ 70°F the right way.

Any help?

EDIT: After a Hard Reboot from Escribe the Room temp started fluctuating, but it's always too high 78,73 °F vs 62,6 °F, could you add a programmable delta correction?

EDIT2: After the first vape after the hard reboot room temperature stops fluctuationg and remains the same, maybe a firmware bug? I'm on latest firmware with Escribe 1.034

EDIT3: The only way to make it work is to do a Hard reboot, soft one doesn't help. BTW Delta correction will be helpfull.

[retird]

Run Case Analyzer and see what the results are compared to the current settings.

[labo]

dc601 said:

Run Case Analyzer and see what the results are compared to the current settings.

I'll try when the battery will be a quarter to half full. I have to discharge it.

However I think that's not the problem... Room temperature reading it's too high compared to real one, even with the device fully charged with no usb current flowing.

And there's the other bug that it stops reading room temperature after the first vape.

EDIT: I think the board saves room temperature as board temperature after a reset and after the first vape, but after a reset the board can be hotter than room temperature or colder, I really don't know where the next reading is scheduled, if there's one. We really need a delta correction, or the possibility to control room temp without escribe or to force a new reading whenever we want

[dsidab81]

The case analyzer will help with this.  Each chassis has different thermal properties, the only way to get this thermal offset is with case analyzer.

it's kind of shocking that these large mod makers aren't customizing this prior to sale.

[labo]

dsidab81 said:

The case analyzer will help with this.  Each chassis has different thermal properties, the only way to get this thermal offset is with case analyzer.

it's kind of shocking that these large mod makers aren't customizing this prior to sale.

I know that but there's something wrong anyway
The board shouldn't store room temp at the very first vape, in my opinion it should to do it when device is not used since x minutes as a background task, updating previous reading
 

[VapingBad]

Mine are accurate if the mod has been standing and not connected to USB for a long time, but soon after starting to use it or even just attaching to atty analyser if starts to climb above room temp (I have put room temp as a display field).  Even with very light use it is 8-10 F over.

[James]

The reason the room temperature stops reading at that point is that the board heats from firing, so the board temperature doesn't reflect the room temperature. It waits until the board is idle again for a reasonable amount of time before sampling again. It may be climbing a few degrees due to body heat.

The Case Analyzer can help if the temperature is off when charging or right after taking it off charging.

How far off is your ohm reading? It may not be due to the room temperature measurement.

[awsum140]

C'mon folks.  The  room temperature sensor is on the board, in an enclosure, with pretty limited ventilation.  Expecting it to read the same as a wall mounted thermometer isn't very realistic.  Any activity on the board will make it read higher.  I'm betting that Evolv is a little sorry they called it "room temperature" rather than "idle board temperature" or "ambient board temperature".

[labo]

James said:

How far off is your ohm reading? It may not be due to the room temperature measurement.

Goliath v2 on a VT200
Dual Ni200 coil 29 AWG 2.5mm diameter 8 Wraps
It should be 0.061 Ohm (from wire wizard)

Atomizer analyzer:
Clean Profile, 210°C, 60W, preheating 200w
Cold Ohm reading: ?
Fire button rapidly pushed, cold Ohm: 0.076
I vape 3 second, cold ohm value rises
I vape 3 more seconds, cold ohm value rises, Cotton is burned, cold Ohm 0.236

Ohm locked profile (0.076 Ohm), 210°C, preheating 200w 1sec
Too hot

Ohm locked profile (0.061 Ohm), 210°C, preheating 200w 1sec
Everything good

For comparison
Eleaf iStick TC40W
Cold Ohm reading: 0.06
Without locking anything that value is stored for the following puffs
Everything good

[James]

Your problem is not the room temperature reading.
In the Mod tab, is a mod resistance set? If not, does anyone know what it tends to be on a VT200?

[labo]

James said:

Your problem is not the room temperature reading.
In the Mod tab, is a mod resistance set? If not, does anyone know what it tends to be on a VT200?

it's not set... I really don't know how it tends to be on my mod

[James]

Based on the numbers you've said, assuming 0.061 is *definitely* the coil resistance (a milliohm meter is helpful to confirm), the resistance of the 510 is significant compared to the resistance of your (fairly low resistance) coil - around 25% - enough to cause a temperature error of (I estimate) 70 degrees C.

This is a problem with lower resistance atomizers combined with higher resistance 510s, and a reason a manufacturer really should measure and fill in the mod resistance. Here is John's post detailing mod resistance, if you want technical details: https://forum.evolvapor.com/topic/65594-topic/?do=findComment&comment=886200

Make sure you are running a recent firmware, 2015-08-07 or newer.

Beyond that, if you don't have a setup to measure mod resistance, and are absolutely sure your coil is 0.061 and it is reading 0.076, that's a difference of 0.015. It is good to leave a little margin (as overestimating can be bad from a control standpoint, and not all the extra resistance is necessarily in the mod). I'd try estimating a mod resistance of 0.012 Ohm and see how it does.

[bingbling]

James said:

Your problem is not the room temperature reading.
In the Mod tab, is a mod resistance set? If not, does anyone know what it tends to be on a VT200?

According to this it's around 0.006ohm.

[VapingBad]

Or the low tech way with a 6.3 mm copper rod (always set it to zero before doing this), if you screw the copper bar in it goes down to 0.004 do this and use the lowest number.

[labo]

James said:

Based on the numbers you've said, assuming 0.061 is *definitely* the coil resistance (a milliohm meter is helpful to confirm), the resistance of the 510 is significant compared to the resistance of your (fairly low resistance) coil - around 25% - enough to cause a temperature error of (I estimate) 70 degrees C.

This is a problem with lower resistance atomizers combined with higher resistance 510s, and a reason a manufacturer really should measure and fill in the mod resistance. Here is John's post detailing mod resistance, if you want technical details: https://forum.evolvapor.com/topic/65594-topic/?do=findComment&comment=886200

Make sure you are running a recent firmware, 2015-08-07 or newer.

Beyond that, if you don't have a setup to measure mod resistance, and are absolutely sure your coil is 0.061 and it is reading 0.076, that's a difference of 0.015. It is good to leave a little margin (as overestimating can be bad from a control standpoint, and not all the extra resistance is necessarily in the mod). I'd try estimating a mod resistance of 0.012 Ohm and see how it does.

I measured mod resistance shorting 510 thread with a huge copper wire, it results 0.004/0.005 ohm, i set 0.045 ohm in mod resistance, according to previous posts it should be fine.
It should be safe due to the fact atomizer resistance isn't considered here and it will always be over 0,001 ohm.

However I finally ran case analyzer and battery analyzer and these are Hcigar VT200 results, do you think are they fine?
 
I attached battery profile, just rename it from .txt to .csv

Moreover, I see that using very low resistance coils like I did will take in troubles in TC mode.
I used 29AWG nickel200 because it's really hard to make a proper coil and insert the cotton with 30 or 32AWG

Then yesterday I made a ribbon wire with 32AWG nickel and 29AWG kanthal
DNA200 reads 2 parallel 7/8 wraps coil as 0.151ohm

I calculated the right temperature curve using steam engine

Like so I have no trouble with TC

I really hope I helped somebody

Labo_Hcigar_VT200_Battery.txt