URWERK EMC TimeHunter X-Ray Limited Edition

Introduced in 2013, URWERK’s award winning EMC concept has re-imagined the traditional watch making techniques by successfully incorporating a complex mechanical watch movement with an electronic brain inside the watch in order to achieve the superlative rates of accuracy.

Inspired by the same innovation, the brand new EMC Time Hunter X-Ray timepiece also combines a precision mechanical movement with an electronic module that monitors its rate. Simply by pressing a button you discover whether your watch is running fast or slow and the amplitude of its balance.

Produced in a limited edition of 15 pieces, the EMC Time Hunter X-Ray offers a high visible time reading with a central dial for black hours and minutes hands coated with white SuperLuminova for enhanced contrast. A rotating disc showing the seconds at 1 o’clock is balanced at 7 o’clock by a power-reserve indicator. The EMC TimeHunter’s performance indicator showing its rate (± 15 seconds a day) and balance amplitude on demand are at 10 o’clock.

The rate of a mechanical watch depends on its position in space as well as its temperature. Before selling a precision watch, therefore, the manufacturer usually tests it by placing it on a continuously rotating arm in a room where the temperature is relatively stable. The watch thus spends the same amount of time in each position. However, in real conditions, the time spent in each position varies according to the working or leisure activities of its owner and for how long the watch is actually on the wrist. Thus two identical watches with different owners might show a different weekly gain or loss. Simply by pressing a button the owner of an EMC TimeHunter watch can find out the rate of his watch — how much it is gaining or losing. He can then adjust it accordingly. This interactive feature enables the owner to adapt his watch to his lifestyle and the changing environment.

The energy for the electronic rating module is generated by turning a crank. When the button is pressed, a hand points to one of two symbols: δ (the rate is being measured) or P (insufficient energy). If the measurement is possible the hand first points to the rate — ± 15 seconds a day — and then, after a short pause, the amplitude of the balance. In addition, a light emitting diode shows green if the watch is performing correctly and red if the rate is outside acceptable tolerances.

While the rate of a watch — its daily gain or loss — can be easily understood, the amplitude of its balance is less obvious. This measures in degrees of arc the swing of a pendulum in a clock or of an oscillating balance wheel in a watch.

In theory, each oscillation of a pendulum or a balance must be isochronous. That is to say that it must be of exactly the same duration, irrespective of its amplitude. In most mechanical watches, an amplitude of between 240° and 310° ensures optimal performance. Since the tiny balance wheel of a watch weighs so little and swings so quickly at four oscillations a second, its amplitude can be affected by a variety of factors. For example, if the balance staff is insufficiently lubricated it will lose amplitude. The amplitude is thus a valuable indicator of whether the watch needs servicing.

The balance is the beating heart of every mechanical watch. Like a human heart, its rhythm (isochronism) and pulse (amplitude) show the state of its health.

The EMC TimeHunter concepts has three aims: to show the effect on the balance of external influences such as the temperature, pressure and the owner’s activity; to allow the owner to adjust the rate of the balance and to encourage the owner to interact with his watch.

The EMC TimeHunter can be described as a precise mechanical watch with a proprietary movement designed, developed and manufactured in URWERK’s Zurich workshops and adjusted by URWERK in Geneva. Its movement complies with the highest quality standards. Its timekeeping functions are adjusted in five positions during a 30-day test to reach chronometer standards.

The EMC TimeHunter movement has the following features:-

  • Its balance wheel is made of ARCAP, an alloy chosen by URWERK for its non-magnetic and anti-corrosive qualities. Its unusual shape has been scientifically calculated to be aerodynamic and minimise the effects of air friction and to achieve optimal amplitude.
  • Its twin mainsprings are housed in two superimposed barrels to ensure a constant power supply and a power reserve of 80 hours.
  • Its exterior adjustment screw, connected to the fast/slow index on the balance, enables the rate to be adjusted by changing the effective length of the balance spring.

The EMC TimeHunter’s monitoring device has the following characteristics:-

  • An optical sensor of the balance wheel, which times each vibration (semi-oscillation) of the 28,800 v/h (4Hz) balance for three seconds. The sensor consists of alight source and a receiver on either side of the balance wheel. Pressing a button on the left of the watchcase activates the measurement.
  • A 16 million Hz quartz resonator constitutes the frequency reference of the EMC TimeHunter. The 4 Hz frequency of the mechanical balance is compared to that of the resonator to obtain the most precise measurement possible.
  • A smart electronic chip calculates the difference (δ) between the rate of the balance and that of the reference resonator. Each microsecond of difference corresponds to a gain or loss of a second a day in the rate of the movement. Thus a variation of 0.0000014 seconds in each vibration translates into a gain or loss of one second a day.
  • A hand-cranked generator. The power for the optical sensor and electronic calculator of the EMC TimeHunter is derived from a generator made by the Swiss Maxon firm, which developed the motors for the Nasa Mars expedition.

On the back of the watch the movement can be seen through the sapphire crystal. Apart from the sophisticated finish of the movement, the key features of the back of the EMC TimeHunter are the adjustment screw and the push-button at the bottom of the dial between the lugs that releases the winding crown.

Noticeable in the movement is the cover of the twin barrels that houses the optical sensors measuring the oscillations. The sensors are linked by a tiny cable to the electronic components to its right, which can be seen behind a lattice. Next to the integrated circuit board can be seen the stacked twin barrels.

Technical details
Model: TimeHunter X-Ray
Limited Edition of 15 pieces

Grade 5 titanium and steel with black PVD treatment
Dimensions: Width 43 mm, length 51 mm, height 15.8 mm
Glass: Sapphire crystal
Water resistance: Pressure tested to 30 m/3ATM
Finish: Brushed and shot peened

Calibre UR-EMC designed and manufactured by URWERK
Escapement: Swiss lever
Balance wheel: ARCAP P40; linear balance with an optical reader
Frequency: 28,800 v/h (4 Hz)
Balance spring: Flat
Energy source: Stacked double mainspring barrels coupled in series
Power reserve:80 hours
Winding: Manually wound
Finish: Open-worked base-plate, Geneva stripes, snailing, sand blasting, Chamfered screw heads

Maxon® hand-cranked generator to charge a capacitor
EMC monitor Optical sensor governed by an integrated circuit
16,000,000 Hz reference resonator

Hours, minutes, seconds, rate indicator δ, amplitude, power reserve,
Index adjustment screw

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