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Discussion Starter · #1 ·
I have a HAQ but don’t know what -/+ 5 seconds per year really means.

I don’t know whether the watches are bell curve weighted around 0 seconds up to the 5 seconds +/- range or it means they are randomly or equally scattered in this 10 second range.

What is the understanding of HAQ experts on this?

What is the probability of having a 0 second sample?
 

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I have a HAQ but don’t know what -/+ 5 seconds per year really means.

I don’t know whether the watches are bell curve weighted around 0 seconds up to the 5 seconds +/- range or it means they are randomly or equally scattered in this 10 second range.

What is the understanding of HAQ experts on this?

What is the probability of having a 0 second sample?
Have you read any of our stickies or done forum searches?
 

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Discussion Starter · #3 ·
Have you read any of our stickies or done forum searches?
The stickies have very useful info and I read the one about assessing watch performance against atomic time. Great but long. A TL:DR version could help.

In the fullness of time I may get around to reading some but I do apologise that I asked a question without doing requisite reading beforehand.

Next thing you know someone will be telling me there's an entrance exam....
 

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Can't really calculate the probability of a point at the mean or any point in the range since no watch maker provides the shapes of the distribution curve, mean, or standard deviation. The +/- 5 s/yr is pretty much just what it looks like a specification, not a statistical term. You may get any result in the range and the watch is considered to be meeting specifications.
 

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...Next thing you know someone will be telling me there's an entrance exam...
The fact that we do not have an entrance exam in this forum shows one thing only: we're a bit masochist... that's all...
 
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The range +- 5 spy is not about getting a good 'sample' or a bad one.
Obviously there will be some that perform better than others.
However, that difference is small compared to the environment.

The spy range in the spec covers the temperature differences of normal use. e.g. some time on the wrist, some off, hot climate vs cold.
5 spy only means something if the temperature range is also quoted.
TC can only do so much. In extreme temperatures you won't get within 5 spy, because the manufacturer assumes you don't leave the watch outside in the desert or Arctic.

If you want to get towards 0 seconds it is a combination of improved trimming (ideally adjusting the TC table to the individual crystal), adjusting this as the crystal ages and controlling the environment.
 
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