Negative Y are usually reported in CS as negative value. But very closed to zero negative values (e.g. -0.000068007834) are reported ad 0.0000, both in Info Point pop up and Measure window, but as N/A in Profile Luma Min.
Honestly I cannot tell if that is an attempt to manage thermal noise - it would be not a bad idea -, but what from a user perspective it is quite puzzling, as from one side he/she sees Y=0 being read at 0 stimulus, and the profile Luma Min marked as N/A. The only way to understand what's happened is to dump the relevant .bcs

Profile dump at 0 stimuls and CS displayed info

Attached file: .bcs file

There is no 'thermal stability' or anything similar managed within ColourSpace, as any such function is always a probe internal process, not a secondary, software one.
Having a negative luma value likely means the K10's black level correction has been performed incorrectly.

And yes, a negative value such as -0.000068007834 will be shown is 0.0000 in both Point Info, and Manual Measure, as that is the first 4 decimal places.
(Remember, no probe is accurate to such decimal places anyway...)

The Min in Settings being shown as N/A is because any negative luma value is invalid.
Maybe we will clip that to zero... but it really makes no different to the end result.

Steve

The point is: anywhere in CS I find Y=0. How can I guess it is a negative luma? Usually you truncate [sign + 4] digit. Should not -0.0001 to be displayed in such a case?
E.g. for -0.00076800783 you display what in attached file.

PS: I know that Klein reports Y with sign + 4 digit precision, but that -0.000068007834 comes from CS averaging following Intelligent Int.

example for -0.00076800783

As we show 4 decimal places, such values will not be shown.
We do not round the value, we just show the four decimal places.
And if the value was 0.00004 it would show as 0.0000 anyway, if we did round...

And no negative value can be used in any calibration calculation, so basically, this is all rather irrelevant, is it not?

Steve

Put this way: I am counter-checking Klein Probe (black) Calibration. Reading 0 I would think I am OK.

For me, as I know that detail, it is irrelevant. I open the .cs and I countercheck. But a plain user? A -0.0000 would make a lot sense.

As said, as no negative values can actually be used in any calibration, it's difficult to see the relevance?
0.0000 is the same as -0.0000, except -0 is not valid in any way.

Steve

-0 tells me that there is something wrong with Klein Black calibration ....
Being something dealing with thermal noise, it may depends on many factors.

As said, -0 is not a valid value, and would cause all sorts of unwanted issues...

Steve

But I can I avoid those unwanted issues if a measured -0.00001 is displayed by CS as a correct 0.0000 without any warning?

In your Klein integration you have clearly chosen to report negative Y. Till I measure a -0.0001, I know about some unwanted issue. If I measure -0.00001 I am exposed to unwanted issues.

So as this not a bug (not even a lack), every time CS displays an Y=0.0000 I should check the value in the .cs file?

No, I mean trying to use -0 causes all sorts of issues with software, etc...
But, we will replace the N/A in Settings with a zero value.

Steve

In fact, this is related to Klein's data transmission method. In Klein's SDK, you can see that it uses a coding function called kfloat to decompose numbers into sign bits, integer bits, and decimal bits. The encoding method for the decimal bits cannot be accurately restored during its reverse process