Hello guys,

My friend has a timegrapher and out of curiosity, I placed one of my vintage chronographs on it.

It has a really erratic reading and that got me a little worried so I went to do some research. It's supposedly fresh from service.

There are suppose to be 2 lines on the timegrapher. Ideally, it should merge into one line. I understand that if there are two lines, it means that there's a beat error. The further apart, the larger the beat error(correct me if I'm wrong). And beat error depends on whether the balance spring is centred(?)

The gradient of the line indicates time error.

The consistency of the lines indicate how healthy the pallet fork is.

This is the reading I had on my "serviced" chronograph

I'm not 100% sure if I understood the information I've researched about how to interpret a timegrapher.

My main question would be that, can a timegrapher indicate that a watch needs to be serviced/hasn't been serviced?
If so, how? And what sorta limitations there are?

Thanks guys!

 

Oh and the amplitude shows how healthy the balance spring is? Ideally a serviced vintage watch should be about 220?

Again. Please correct me if I'm wrong. Thanks guys!

 

first of all, check your lift angle. 52 is correct for alot of watches but not all.

 

You're not quite right in what you say but, have a look at this - pages 4-15 and that'll give you a good idea of what the timegrapher is measuring. And you'll need the lift angle so, let us know the calibre.

You seem to have a snow storm. I suspect that you didn't have the gain on the microphone set high enough as these cheap timegraphers are not very easy to use. The crown should be against the microphone end (not the sliding end) and the watch face up. Then use the two buttons on the right to increase or decrease the gain.

Out of interest, did your watchmaker supply you with a picture of his timegrapher results? Or was it bought as "serviced"?

Cheers, Chris

 

Ah. I can't seem to identify the movement so I can't find the lift angle. Does anyone recognise this movement?

 

Can't seem to upload the image. Weird.

 

Here is the listing
https://www.ebay.com/itm/272620834488Purchases made through these links may earn this site a commission from the eBay Partner Network

 

Judging from the photos in the eBay listing, the movement was NOT serviced. This is corroborated by the low amplitude. It might increase when you enter the proper lift angle, but it won't increase that much. The watch needs a full service and a new mainspring. Sorry........

 

Hello Chris,

Thanks for the link. I've just read up on it briefly. A lot of technical details which I am struggling to digest but I think I understand the gist of it. I looked at the examples of the graphs and the closest one to mine that I could find said "insufficient amplitude; overhaul" nevertheless, I don't think my graph's pattern is identical to any of those inside.

I did press the up button all the way and I've correctly placed crown to metal plate on the microphone.

The photo is taken by me using my friend's timegrapher.

Thanks for your reply Chris!

 

Assuming there is enough audible signal to the microphone as @ChrisN mentioned then service is needed. As a sanity check, how accurate is the watch when you compare to a reference timepiece over 24 hours?

 

I'll let you know tomorrow!

 

Hmm. True. The movement doesn't look clean in the listing. Guess I should have been more prudent with my purchase.

 

Venus 170.

 

That's a shame. It does seem like the reading is real and, as has been noted, it needs a proper service.

That Witschi document is quite complicated and I should have just pointed to the graph interpretation pages but, you found them anyway.

Hope you find someone who will service it as it looks like an interesting watch.

Cheers, Chris

 

I'm afraid your watch is in dire need of a professional service, despite what the seller said. The graphs you have seen on-line tend to represent how individual problems with a movement show up, however, yours has loads of them all mixed up. A service by a competent watchmaker should sort them all out, the important word being competent.

As far as using that timing machine is concerned; given the price, these are actually surprisingly good machines (I have one). They don't have the level of precision (e.g. decimals of a second/day) that the expensive machines have, and lack a number of other diagnostic options that are useful to a professional.

They won't calculate the correct amplitude for co-axials either, they don't have aged crystals for long term stability, and despite having a USB port for calibration, I've never figured out how to do it, or indeed if it is possible. Probably cheaper to chuck it and buy a replacement anyway !

I'm sure your friend who owns the machine knows how to use it anyway, but some of the info you were given earlier may not be correct.

- There is no gain control, it is automatic. Those buttons on the right control other aspects of the machine.

- The watch is normally mounted with the crown on the right (in the recess in the sliding part) not the left.

You do need to use the correct lift angle to get an accurate amplitude reading, but I think that is the least of the problems at the moment.

Look forward to seeing it once fixed. Good luck.

Edit: It's always possible that something may have happened to the watch in transit - the hairspring getting hung up or something like that, which would create havoc. Also, having looked at the listing, that movement has no shock protection, so is vulnerable to being bashed around. A good watchmaker should quickly diagnose what needs to be done though.

 

I have that exact machine and it is a very useful tool for ascertaining the truth of claims of health or recent servicing and are pretty cheap at around £120. In my experience, with an eBay watch, unless they can provide documentary proof of a service having taken place, any claims are just bs and you should assume the worst. The watch trace shown above is typical of a eBay watch in dire need of a service. Some of these clowns will shake a watch and if a hand moves claim that it is healthy.

 

Sadly have to agree about ebay sellers in general.
Agree 100% about the timegrapher - I've sent a couple of watches back for rectification after supposedly (and expensively) being "serviced and running to manufacturer specifications" by authorised repairers. * Well worth the outlay compared against the cost of even a single service.
* I won't name them, but for the avoidance of doubt, I have never seen either of them post on here or any other watch forums.

 

I used to have one of these machines but now use one by Witschi who make probably the best ones. On my cheap 1000 timegrapher, the buttons on the right control the gain of the microphone when it's being used. They do other things when scrolling through menus. Try it and you should see the gain scale increase somewhere on the display.

Regarding placement of the watch, it should be with the crown against the sensor. Here is an extract of the Witschi manual. I am not showing the part where they say something along the lines of "incorrect placement maybproduce distorted results"....



Hope this helps, Chris

 

There is no gain adjustment on my model 1000. That said I have never needed to adjust the gain, it picks up a signal just fine on everything I have used it on.

 

That's odd, perhaps there are different models. Just in case I'd forgotten how mine worked, I just dug it out. It appears to be a "no name" model....

When the watch is running, you can adjust the gain with the right hand arrows. Here is max gain and you see it on the upper right of the screen. The line is pretty good in this instance (it's a cal 601 I'm wearing). This watch is fine.



Here I've reduced the gain using the buttons (I think you're right that the auto gain works in most situations and is probably in the middle of the scale). Now the line is hopeless and the watch appears to have some issues.



And here on the Witschi which is a lot easier to read. I know people will read into this that the cheap ones are accurate within a few degrees of amplitude and a few seconds per day - but my sample size is 1 The Witschi obviously has a calibration document and needs refreshing on a fairly regular basis.

Regards, Chris