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HYT - HYT in figures

HYT HYT in figures

We consider just how many decimal points HYT has to take into account when developing and producing its unique timepieces.

HYT has both invented and mastered a completely new way of displaying the time. Although the mechanical watch movement powering HYT’s technology is an excellent example of the traditional watchmaker’s art, an impressive amount of development and expertise has gone into perfecting the fluid display used in every HYT watch. The magnitude of this accomplishment is difficult to put into perspective, since HYT is doing something that no other watch brand, or indeed any other company, is capable of. We thought a good way of showing how HYT is combining the talents of the engineers in fluids, micromechanics, optics, chemistry and electronics working at Preciflex (the company that supplies the display module) would be to explain some of the figures you will hear on a visit to their workshops.

This is the amount of displacement of the thermal compensating bellows (inside one of the main bellows) required to compensate for a one-degree Celsius temperature fluctuation. The fluid inside these smaller bellows has different properties to the two fluids used in the capillary for displaying the time. Without this thermal compensator, the display in the capillary could fluctuate by up to three minutes for every one-degree Celsius temperature fluctuation.


The cam stroke acting on the bellows is approximately 1mm and the circumference of the capillary display is 100mm. Any error is therefore multiplied by a factor of 100, so a deviation of just 1.5 microns (0.0015mm) can put the time display out by one minute. Anything over two minutes is actually visible on the display.

This is the diameter of the nozzle in the flow restrictor inside the capillary that regulates the flow of the two fluids around the capillary and thus prevents “breakages” in the meniscus that indicates the time.

A total of 500 microlitres (0.5ml) of fluid is used in the capillary that displays the time.

This is the thickness of the walls of the capillary. The inside of these walls has been coated to ensure that they remain hydrophobic and oilophobic, preventing any fluid residue from adhering to them and leaving traces. There is actually an optical effect from the watch crystal that makes the capillary look bigger than it really is.


It takes one year to develop a new fluid colour. All the research, development and testing is done in-house at Preciflex by a chemist. The crucial factors considered are how the fluid will age, whether it will retain its colour, how it will react with the colourless fluid and how it will flow through and interact with the capillary.

This is how long it currently takes, in hours, to prime each capillary. The two fluids are injected and retracted numerous times to remove micro bubbles of air. This is done by hand for every capillary and it requires two months of training for an operator to be able to do this. Preciflex is working on a semi-automatic process in which the priming will be done in a vacuum to avoid the problem of air bubbles. It will take around 30 minutes to set up the system but only 30 seconds to do the actual priming.


The number of colours currently available in HYT watches: green, blue, red and black.

The number of engineers working at Preciflex, specialised in fluids, micromechanics, optics, chemistry and electronics.

The number of patents filed by Preciflex, 8 of which have been granted.

The speed, in revolutions per minute, at which the microgenerator powering the LED in the light module of H4 operates. The LED itself shines at a frequency of 1,200Hz.

As you can see, HYT works at tolerances down to a level below the micron and has pioneered new technologies and processes not just in the watch industry, but in the micromechanics industry as a whole. A number of actors in the pharmaceutical industry, for example, have already expressed an interest in the technology and its potential application in micro-injections. What started with a crazy idea for a watch has turned into a promising new business.

The brand

The pioneers of “fluidic time” have become specialists in something that had long been thought impossible: combining mechanics and fluids in a wristwatch.

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