Testing My GMT Master II with Kello For The iPhone

Testing My GMT Master II with Kello For The iPhone

Nov 22

I recently downloaded Kello from the iTunes App Store and thought I’d share my experiences with this iOS application.

Jon Edward’s Kello is an app for measuring the accuracy of a mechanical watch and show you many seconds per day your watch is gaining or loosing.  I first became aware of Kello back in July – apparently the app was first released earlier this Summer, but developer Jon Edwards quickly removed the app from the iTunes App Store and went back to the drawing board after an avalanche of negative feedback from early adopters.  Recently however Edward’s re-released Kello, and it is again available for $8.99.  You can read more about Kello’s development history here.

For the mechanical watch enthusiast, the capability of having watch accuracy tester on your iPhone is valuable on many levels.  From a cost standpoint, $8.99 is peanuts compared to the several hundred dollar outlay necessary to buy traditional watch testing machinery.  Such devices are normally out of the reach of most watch enthusiasts, and typically only used by watch servicing professionals.  So for many, Kello brings a cost-effective capability that many watch owners and enthusiasts would not have otherwise.  Portability is also another tremendous advantage – I happen to own watch testing equipment, but it’s not something keep with me.  So having a portable solution would definitely come in handy – wouldn’t it be nice to be able to test the accuracy of watch you were considering buying?

To test the capabilities of Kello, I decided to break out my most accurate watch – my ultra-rare Rolex GMT Master II with the Rolex Caliber 3186.  I first tested it using my Orbita Mechanical Watch Tester:

If you click on the above photo and see the larger view, you’ll see according to the tester (lower left hand corner of the blue screen) my watch is running an impressive +.3 seconds per day.

Now it was time to see what Kello could do.  I plugged my headphones (with built in mic for talking on the phone) into my iPhone 4, and placed the watch on top of the microphone.  In order to calculate the accuracy of a watch, Kello needs to know the beat speed of the balance wheel it’s testing.  You can manually select the beat speed if you know, or Kello can determine the beat speed automatically.  On this first run, Kello was able to automatically and accurately determine the beat speed of my GMT’s balance wheel and everything seemed to go extremely well.   Here’s the readout I got from Kello:

I was pretty impressed!  Right off the bat, Kello gave me a reading which matched the reading from the Orbita Mechanical Watch Tester.  I decided I try and take a couple of photos of my watch and my iPhone running Kello for this article, so I did another run.  That’s when the problems I experienced with Kello started happening.

I did about 5 additional test runs with Kello, and each run yielded significantly different results.  I consulted the in-app help file, and read that it was recommend to place the iPhone headphone on a sound-dampening soft cloth or towel, then placing the watch on the microphone.  I tried that, and my readings were still all over the place – ranging from about +10 to -11 seconds per day.  I’m sure the main Achilles heel of this app is relying on the iPhone’s headphone mic as the sensor to take the balance wheel readings – it just wasn’t designed for that purpose.  Is it worth $8.99?  Probably, yes.  If you are patient with it, and take several readings to make certain of your results, I think it is possible get accurate readings from Kello.  And of course, there’s always the hope that subsequent versions of Kello will figure out a way to overcome or compensate for the iPhone mic being a poor sensor.

UPDATE – GIVING KELLO A SECOND TRY

After my initial frustration of trying to get good, consistent results with Kello, I decided to give it a second go, this time with a Submariner 116610.  What bugged me from the first session was the fact that I was able to get results which matched my professional grade watch testing machine once.  Perhaps if I just changed the test conditions correctly, I could hit upon the right conditions for getting good, consistent results.

The first step was to again establish a baseline for comparison with my Orbita Watch Tester.  This Rolex Submariner 116610 was running quite consistently at near-perfect accuracy levels of +/- 0 seconds per day deviation.  Outstanding!

Now I attempted to test the watch with Kello.  This time, I placed the mic on a cloth (as recommended) and placed another cloth over the watch to further protect from ambient noise.  Unfortunately, Kello could not acquire enough signal to get a proper reading under these conditions:

I tried cranking up the amplification slider too – to know avail.  This had me perplexed and quite frustrated.  I tried stopping the application and re-running it, checked the headphone connections, and played with the mic – each time with the same disappointing result.

Finally, I tried just holding the watch in my fingers, while holding the mic on the crystal.  I thought perhaps the sound generated by the balance oscillating would be more easily detected through the crystal.  Almost immediately Kello got signal acquisition, and generated rate results identical to the professional grade watch testing machine:

I repeated these steps several times and got consistent results each time.  From these two sessions I made a few conclusions:

-Using Kello isn’t a “done in one” process.  You’ll likely need to really “play with it” to get an accurate reading.  Again, this isn’t necessarily a failure of the Kello app but rather of needing to use a mic that wasn’t designed for use with Kello.

-The conditions required to capture accurate readings could well depend on the watch being tested.  You’ll need to try a lot of different testing variations (mic placement, watch placement, use of sound dampeners, etc.).  Don’t assume one set of conditions (such as those recommended in the in-app help screen) will work consistently for every watch.

I feel more comfortable now recommending Kello.  I think a lot of “gear head” watch enthusiasts will enjoy playing with the app and testing their watches with it.  Finding the optimal testing conditions for a given watch will be half the fun for some.  And for $8.99, it provides a lot of utility given the alternatives.