Bell & Ross +12.5 secs a day

[Barrisimo]

I bought a Bell & Ross BR V2-93 GMT as a slightly less attention grabbing watch for travel. I have had it on a lot over the last two weeks whilst on holiday. Checking on a timing app it is running around +12.5 secs a day. What is the thought on that is that acceptable or a bit on the poor side? How far out would justify a return on a watch of that level? Thanks.

[walkerwek1958]

Do you trust the timing ap?

Suggest you check it against something else, I always use a quartz analogue watch or a website that I know is correct.

12.5 secs us a lot, it won’t take many days to verify it. Suggest check it morning and night, then leave it dial up overnight. That’ll tell you what it’s doing on the wrist and what its doing overnight. Wearing it to sleep introduces more variability.

A gain of this magnitude is disappointing and provided the watch is running well it could be addressed by regulation. Suggest you get more data as I’ve suggested to back up what you've seen. Here’s a silly question but I’ll ask it, did you alter / reset the watch to correct for different timezones during the holiday?

[AlexM]

+12.5 would be unsatisfactory for that watch if it were mine. As Paul said, best to check in a few positions as figures can even themselves out to an acceptable average.

[Omegamanic]

What is the spec for the movement?

Possibly email B&R and ask them to confirm the spec specification - they may have one, and it may or may not be outside expectations.

[Barrisimo]

What is the spec for the movement?

Possibly email B&R and ask them to confirm the spec specification - they may have one, and it may or may not be outside expectations.

It is an ETA 2893-2. My timing App Twixt is probably fairly basic but everything else from Omega, Rolex, IWC, JLC that I have run at timing numbers inside spec. I did adjust the watch for the timezone but actually checked it over several days after setting the time.

[ENES]

The watch could be magnetised?

I have had this with a few mechanical watches that are usually accurate, but start to gain excessive time when I wear them to work.
Something in my office or at my desk seems to magnetise the watches (keyboard, laptop, monitor - who knows).
I put my mechanical watches right with a cheap demagnetiser bought on eBay - it's a 2 minute job. The watches are then back to their usual accuracy & show no reading on a gauss meter - until I start to wear them to work again!

I solved this problem by buying a Tudor watch with a silicon hairspring!

Could be worth buying a demagnetiser & giving it a go - especially if you have just bought the watch & do not know where it was worn previously.

[Omegamanic]

I doubt it's magnetized if it's running at 12.5 seconds, rather than minutes.

Some brands are much better at regulating than others - some just place the movements in the case and rely on the manufacturers spec figures:

Tag Heuer's website for example states:



Quartz movement: between -1 and +11 seconds per month
Standard automatic: between -5 and +20 seconds per day
Chronometer: between -4 and +6 seconds per day

So +12.5 would be well within spec. As I'm fairly sure would be the case with a number of other watch brands.

[troymcclure72]

The watch could be magnetised?

This, my br01 was a nightmare for getting magnetised. Would run up to + 5 mins a day! Demagnetising sorted it.

[seabiscuit]

This, my br01 was a nightmare for getting magnetised. Would run up to + 5 mins a day! Demagnetising sorted it.

But there’s a world of difference between plus 12.5 seconds and plus 5 minutes a day. Regulating the movement rather than demagnetising it would likely improve matters.

[ENES]

But there’s a world of difference between plus 12.5 seconds and plus 5 minutes a day. Regulating the movement rather than demagnetising it would likely improve matters.

If it were me, I would want to make sure it wasn't magnetised.
Hold a compass over the watch or download a free gauss meter app for your phone & move the watch around under your phone to see what sort of readings it gives.
At least that way you can easily discount (or not) the possibility of a magnetised watch, without spending any money or having any hassle returning the watch.

I certainly wouldn't be happy with a watch of that price / quality gaining +1.5 minutes per week.

[walkerwek1958]

If it were me, I would want to make sure it wasn't magnetised.
Hold a compass over the watch or download a free gauss meter app for your phone & move the watch around under your phone to see what sort of readings it gives.
At least that way you can easily discount (or not) the possibility of a magnetised watch, without spending any money or having any hassle returning the watch.

I certainly wouldn't be happy with a watch of that price / quality gaining +1.5 minutes per week.

How do these gauss meter aps work? Struggling to get my head around that.

When watches are magnetised it’s the balance and movement parts that are affected, I’m not at all convinced by the ‘compass test’.

Usually, a magnetised watch will run significantly fast, not just a few seconds/day.

Checking the rate against 2 other sources (as I’ve suggested) should be the next step, if the watch is really gaining 85-90 secs/week I would ask for it to be regulated.

[Bluehase284]

How do these gauss meter aps work? Struggling to get my head around that.

When watches are magnetised it’s the balance and movement parts that are affected, I’m not at all convinced by the ‘compass test’.

Usually, a magnetised watch will run significantly fast, not just a few seconds/day.

Checking the rate against 2 other sources (as I’ve suggested) should be the next step, if the watch is really gaining 85-90 secs/week I would ask for it to be regulated.

A magnetized watch had its timing thrown because the hair sitting is attracted to the next coil and touches, effectively removing one or more coils. This is why the rate change associated with magnetization is normally large.

Whilst it is the hair spring that causes the issue, it is likely to be the case, screws etc that are magnetized and holding a feild that the hair spring is sitting in the middle of.

Phones have magnetic sensors in the form of the internal compass. They use this sensor to look for magnetic fields.

[Berty234]

I’ve had two or three watches that have randomly jumped up about 10 secs faster per day. They were all slightly magnetised - a quick run over a demagnetiser and they returned to stellar performance. Try it, buy one on amazon.

[ENES]

The apps work & will easily show if a watch is giving off a magnetic field.
Check before & after demagnetising the watch - you will see the difference.

Only demagnetise when the watch has fully stopped / unwound though!

[helidoc]

I don’t think it is magnetised. I would measure it dial up, crown up, crown down for a few days first. I use the WatchTracker app. I wouldn’t expect COSC (-4 to +6), but not much beyond that.

I would get a bit more data first


Dave


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[Barrisimo]

Thanks everyone all very helpful comments. I shall investigate further.

[JGJG]

I have found my Bell & Ross ETA of noughties vintage to be a top-drawer timekeeper and would be surprised if that is no longer the case.

OP - how does the watch rest overnight? If dial up, it might well be worth trying crown up....

[walkerwek1958]

A magnetized watch had its timing thrown because the hair sitting is attracted to the next coil and touches, effectively removing one or more coils. This is why the rate change associated with magnetization is normally large.

Whilst it is the hair spring that causes the issue, it is likely to be the case, screws etc that are magnetized and holding a feild that the hair spring is sitting in the middle of.

Phones have magnetic sensors in the form of the internal compass. They use this sensor to look for magnetic fields.

Thanks, I didn’t know phones had magnetic sensors.

I understand how magnetism affects the behaviour of the hairspring, I’ve come across it several times. The amplitude also falls markedly so a quick test on the timegrapher will usually point towards a magnetised watch if a combination of low amplitude and high rate is observed.

I’m not sure whether stainless steel can become sufficiently magnetised to create a field that’ll influence the hairspring. Movements running outside the case still exhibit the effects of magnetism, I’ve see that plenty of times.

First thing I do when checking a watch is demagnetise it and look for any difference in rate and amplitude. After removing the movement I usually demagnetise it again before further examination.