Watch testing

[TommieD]

I'm buying a used Rolex and they have time and pressure tested it. What do these numbers mean?

imgur. com/a/aGU3e1a

[hsfrank]

It appears to be a reference on the website imgur.com

[TommieD]

I'm a newbie so I can't post links. Take the space out between imgur. and com

[hsfrank]

Take the space out between the ‘r’ and the ‘.’ And it will give you this picture. I will leave it to experts to explain the results.

[kauffee]

The pressure tests on the left at negative and positive pressure are for water resistance. All looks good.

The right is the timekeeping from a timegrapher. The leftmost column is the watch position... dial up, dial down, crown down, crown left, etc. The second column is how many seconds per day it's running in each position. So it's running a bit fast but not too bad. Leave it crown down overnight. Hard to say how it will run on the wrist, too.

[TommieD]

Originally Posted by kauffee

The pressure tests on the left at negative and positive pressure are for water resistance. All looks good.

The right is the timekeeping from a timegrapher. The leftmost column is the watch position... dial up, dial down, crown down, crown left, etc. The second column is how many seconds per day it's running in each position. So it's running a bit fast but not too bad. Leave it crown down overnight. Hard to say how it will run on the wrist, too.

Thanks! Any concerns about the change in Amplitude?

[77T]

For the pressure test, just know that in a vacuum (negative pressure) the watch expands a bit. In a positive pressure test, the case deflects as pressure increases.

First test, -.4bar, is a vacuum test. Realistically you only experience this mountain climbing above 14,000 feet or on an airplane for a flight without pressurized cabin. So under a mild vacuum it expanded to a maximum of 2.71 microns thicker than under normal pressure. And while under that vacuum for several seconds it varied 0.00%, meaning it never leaked. Up to 1.0-1.5% is considered an acceptable leak-down rate.

Second test is a pressure test for compression under water pressure or going down into a diamond mine. Under a pressure of 3bar (3 atmospheres which is about 100 feet) it deflected 19.97 microns and then varied 1.0% per minute over the time the pressure was applied. Good enough for recreational diving.


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[TommieD]

That's good to know about the pressure test, doubt i will be going more than a few feet into the water with the water.

[MinMay]

How old is the watch? The amp is low if it's a modern watch. If vintage, then it's normal.

[TommieD]

Originally Posted by minmay

how old is the watch? The amp is low if it's a modern watch.

2009

[MinMay]

Originally Posted by TommieD

2009

I'm not an expert, but it's on the low side of "good" for a 2009 watch. If you google about amplitude, then it should be in 250-300 range as good. Also, it depends on how long it was running before the test. If X is the average, then it should be okay...

Do you know when was the last service done? I think +-2 secs is ideal for Rolex modern watch. You'll need to find if 4secs running within the COSC specs.

Overall, it's nothing to be alarm about....

This thread should be in the WatchTech section.