iSpindel - Default Polynomial - Impact Readings?

[higginsg]

Yesterday I did the sugar water method on two iSpindels that I had working some time ago. I did not change the Polynomial back to the default prior to doing the sugar water calibrations.

Values of Polynomial for two iSpindels while doing the sugar water method:
#1: -0.00031tilt^2+0.557tilt-14.054
#2: 0.8357+0.009305tilt-0.0001545tilttilt+0.000001048tilttilttilt

My new readings for each iSpindel after doing the sugar water calibrations:
#1: 0.8671+0.007988tilt-0.0001382tilttilt+9.9453tilttilttilt
#2: 0.8523+0.009463tilt-0.0001754tilttilt+0.000001272tilttilttilt

I noticed that #1 has a 9.9453 at the end of the new reading prior to the tilttilt*tilt and #2's new readings are way off with all the zeros. I also put Spindel #1 into my wort and it's reading at 1.010 while my hydrometer has the wort at 1.055 (it's reading wrong including the tilt value).

My questions:

1. Was I supposed to put the default polynomial back in the iSpindel prior to doing the sugar water calibrations of -0.00031tilt^2+0.557tilt-14.054 (this is the default Polynomial formula if I'm not mistaken)?
2. Why are the third numbers in each set of number (prior to tilttilt*tilt) so different (Update README.md #1 with 9.9453 and Schlitten #2 with 0.000001272)?

Thank you!

[thegreatgunbantoad]

It doesn't matter what the poly is during your readings as you should only be reading the Tilt reading from the iSpindel. Your gravity should be being read by a hydrometer or other know calibrated external method, not from the iSpindel.

See if this sheet is easier to use: https://github.com/universam1/iSpindel/blob/master/docs/ManualPolyGenerator.xlsx
It uses brackets to ensure the calc is legal and E notation to keep the poly length down. There used to be an issue with long polys getting cropped.
You'll need to download it btw.

[thegreatgunbantoad]

Difficult to answer why your numbers are different without your data and knowing which calculation method you used.

[higginsg]

Thank you for the quick reply - I was away from home - apologies for my late reply.

I've attached the readings I took in the spreadsheet and the polynomials it generated.

I'd appreciate it if you'd have a look and tell me if I'm doing something wrong!

I did the easy calibration method here.

tilt.xlsx

[thegreatgunbantoad]

@higginsg
First thing of note you have cut the 'e-7' out, don't do that it's very much needed.

Edit:
Yeah I think that was pretty much it. Have a look in here for an alternative format:
tilt_response.xlsx

TL:DR:
Use https://github.com/universam1/iSpindel/blob/master/docs/ManualPolyGenerator.xlsx to get:

iSpindel 1:	(9.9453E-7*(tilt^3))+(-1.3826E-4*(tilt^2))+(7.9887E-3*tilt)+(8.6720E-1)
iSpindel 2:	(1.2725E-6*(tilt^3))+(-1.7544E-4*(tilt^2))+(9.4635E-3*tilt)+(8.5234E-1)