iSpindel gravity correction on cold crash.

[MonTage69]

Noticed that when cold crashing the gravity goes up.
20C = 1.011
2.5C = 1.020

Maybe this is purely on the iSpindel side.

Pretty sure my calibration was done correctly as it's always been pretty spot on on my manual readings within 0.001 of a point.

I know the tilt is able to adjust.

Any pointers?

[thorrak]

The iSpindel only transmits angle - not gravity - so there is no "temperature correction factor" applied on the device.

It's not a bad idea to build functionality into Fermentrack to apply a temperature correction factor. I'll use this issue to track against that feature.

[MonTage69]

Thanks @thorrak

[pppedrillo]

@thorrak
iSpindel sends both a gravity (calculated using user input polynomial) and a raw tilt(angle) for all the supported services. Try to lookup for gravity var in received data.

@MonTage69

[pppedrillo]

It's not a bad idea to build functionality into Fermentrack to apply a temperature correction factor. I'll use this issue to track against that feature.

FYI iSpindel will soon have its own ATC functionality, but it will be optional (eg can be turned on or off).

[MonTage69]

Agree, should just be optional

[ChrisThomas42]

I didn't spot this earlier in either Fermentrack or iSpindel so even though a bit late to the party. Having temperature correction factor applied to SG would be a good thing, if the correction is best being applied by the iSpindel or in Fermentrack is debatable.

Looks as if the ATC feature hasn't got enough support in the iSpindel community though. If that's the case Temperature Correction applied in Fermentrack?

[pppedrillo]

Looks as if the ATC feature hasn't got enough support in the iSpindel community though.

@ChrisThomas42 Not community. By some reason it basically has got no go from iSpindel project owner.
But so far looks like Fermentrack has the same level of interest to this feature :)

[thorrak]

Looks as if the ATC feature hasn't got enough support in the iSpindel community though.

@ChrisThomas42 Not community. By some reason it basically had no go from iSpindel project owner.
But so far looks like Fermentrack has the same level of interest to this feature :)

I mean... If someone wants to implement it, we can always add a flag to the iSpindel model to selectively apply it. The pull request button is at the top of your screen. ;)

The interest is implicit in the fact that there's an issue open against it, it just unfortunately isn't something I've yet had time to dive into.

[ChrisThomas42]

Looks as if the ATC feature hasn't got enough support in the iSpindel community though.

@ChrisThomas42 Not community. By some reason it basically has got no go from iSpindel project owner.
But so far looks like Fermentrack has the same level of interest to this feature :)

By community I meant the wider user community, sorry. I was hoping that posting about this feature on UK and USA Homebrew forums it would spark a bit of interest. In 24 hours, across both forums only 3 yes's!

[thorrak]

Per this site the formula for this appears to be the following:

Hydrometer Temperature Correction Formula

CG = corrected gravity
MG = measured gravity
TR = temperature at time of reading
TC = calibration temperature of hydrometer

CG = MG * ((1.00130346 – 0.000134722124 * TR + 0.00000204052596 * TR – 0.00000000232820948 * TR) / (1.00130346 – 0.000134722124 * TC + 0.00000204052596 * TC – 0.00000000232820948 * TC))