Sinn Technology Glossary
Glass-like product made from polyacrylic esters.
It is highly break resistance and is resistant to weather and corrosion. Small scratches can easily be polished out.
Distance of oscillation (swing or beat).
The amplitude is the maximum angle of rotation of the balance between the point of equilibrium and one of the reversal points of the oscillation. The average amplitude values of most watch movements made today are between 250° and 300°. As the lubricant ages, this value gradually falls.
DIAPAL Technology deals with this problem at the root, by dispensing with the need for oil altogether.
Devices or equipment, the functions of which are protected from magnetic interference by the use of suitable materials and/or screening up to a specified level, are antimagnetic.
When light hits a glass surface it splits in two: one part of the light is bounced back as a reflection, the other goes into the glass. Reflections severely impair the readability of a watch; they reduce both the light permeability of the crystal and also the clarity of the image. Diffuse points of light and reflected images in non-antireflective glass can in some cases be more dominant than the dial itself.
A very thin coating of a suitable translucent material is used to make glass anti-reflective. This coating is generally vapor deposited onto the glass in a vacuum. The splitting of the light mentioned above then takes place both on the surface of the glass and also on the surface of the thin anti-reflective layer. The light reflected from this layer overlaps with that from the glass itself. The layer needs to be thick enough for the light reflected from the different surfaces to cancel each other out through destructive interference. Destructive interference, in simple terms, is when two opposing waves are offset so that the peak of one wave always coincides with a trough of the other, thereby canceling each other out. Such a displacement occurs because the light reflected from the surface of the glass has to travel slightly further than that from the surface of the coating to ensure overlapping. A further precondition for mutual cancellation is that both waves must have the same amplitude. Multiple layers with different types of coating and thicknesses are required to create an anti-reflective effect at different wavelengths (colours) of visible light.
Sinn’s sapphire crystals are always coated on both sides to ensure optimum readability. Colorless anti-reflective coatings are used, created using a precision-controlled coating technique, to ensure that the dials show their true color.
A particularly hard, glass-like anti-reflection coating is used in our 900, U1, U2, U1000 and UX models. At 1800 to 1900 HV it has almost the same degree of hardness as sapphire crystal (approx. 2000 HV) and is applied using a special sputtering technique. This technique allows reflection to be reduced to less than 0.5 %.
According to DIN, watches which do not stop when exposed to a magnetic field (see magnetism) and the accuracy of which does not exceed specified limits when exposed to a magnetic field may be described as antimagnetic.
DIN guideline 8309 stipulates that mechanical watches are antimagnetic if their rate change does not exceed +/- 30 seconds per day after exposure to a magnetic field of 4,800 A/m (corresponds to 6 mT) (movement diameter larger than 20 mm). The watch should also not stop when exposed to a magnetic field of this strength.
Mechanical watches react to magnetic fields primarily due to the fact that they contain temperature-compensating hairsprings (see Nivarox).
Sinn offers additional magnetic field protection in some models, which provides effective shielding up to a field strength of 80,000 A/m. This exceeds the DIN regulations by a factor of more than sixteen.
Sinn technology to reduce ageing processes inside the watch.
See Sinn Technology Ar-Dehumidifying Technology.
The balance, in combination with the hairspring, constitutes the oscillation system of a mechanical watch.
Balances nowadays are nearly always closed metallic wheels with two or three spokes. The hairspring is firmly fastened to the balance shaft. This allows the balance to execute a rotary oscillation which is ultimately responsible for the even running of the watch.
The to-and-fro motion of the balance is translated by means of a small ruby pin (ellipse) into to-and-fro rocking of the anchor. Within this rhythm the anchor, in turn, inhibits the anchor wheel and therefore the entire gear train of the watch (escapement).
The balance is normally made from an alloy called glucydur. This is a type of beryllium bronze. This considerably reduces the influence of temperature. The residual temperature error is compensated by the Nivarox spring.
Physical unit of pressure, i.e. force per surface area.
One bar corresponds roughly to the average atmospheric air pressure at sea level. Water (hydrostatic) pressure increases by approx. one bar for every 10 m of water depth. A watch is therefore subjected to one additional bar for every 10 m of diving depth (quod vide pressure resistance and water-resistance).
Black Hard Coating
See Sinn Technology Black Hard Coating.
Outer bezel with a special design to prevent it from being lost.
Bezels are conventionally attached to the body of the case using a snap-in mechanism. If knocked, the ring can, in the worst case, become detached and the set time lost. Many our watches are therefore fitted with a safety system which overcomes this design weakness.
The design is based on an elastic, unsealed loss-prevention ring located in the interior of the bezel. A number of screws in the side contract this ring until it bridges the gap between the bezel and the case. Only by removing the screws does the loss-prevention ring relax and retract from the gap, allowing the bezel to be removed from the case.
A chronograph is a timepiece with a stop mechanism which can be used to time the length of a particular procedure.
Conditions which movements must meet to fulfill the chronometer standard.
Watches or movements with particularly accurate running, confirmed by an official certificate, are designated chronometers. Chronometer movements have to be given a serial number to ensure that the certificate and the movement can be uniquely matched. Chronometer tests are currently carried out and documented almost exclusively by the C.O.S.C. (Contrôle Officiel Suisse des Chronomètres, an independent public-service organization in Switzerland). Just recently, however, the Landesamt für Meß- und Eichwesen Thüringen (Thuringian State Office for Measurement and Calibration) in Glashütte has started offering chronometer tests as the accreditation office of the German Calibration Service in Germany.
The chronometer quality of a mechanical watch movement is determined in part by the special workmanship of certain movement components, partly by precise regulation of the watch. We only use the highest quality products provided by Swiss movement manufacturers in Sinn watches. Basically all these movements can be regulated as chronometers. If desired, our watches can be given a fine-adjustment, i.e. they are of chronometer quality, but are supplied without a certificate. We generally only provide chronometer certificates on request, on account of the disproportionately high surcharge.
The specifications of a mechanical chronometer movement include a number of rate accuracy aspects: e.g. the effect of position on the rate, the stability of the rate in each individual position and the temperature dependency of the rate. There is an international standard (ISO 3159) for mechanical movements which correspond to national standard systems (DIN 8319, part 1 and NIHS 95-11).
Because the accuracy of a mechanical watch generally depends on its spatial orientation in the Earth’s field of gravity, five test positions for observing the escapement are distinguished (e.g. “dial top”, “dial bottom” etc.). The mean of the accuracy values measured in the five test positions should remain within a range of -4 to +6 seconds per day (24 hours) at room temperature (23ºC). This standard, by itself, is not particularly exacting and would probably be fulfilled by any modern mass-production caliber. However, a chronometer movement must also achieve this mean value with no appreciable accuracy differences between the individual positions. The largest accuracy difference between an upright and horizontal position (more precisely: between “crown left” and “dial top”) should be no more than -6 to +8 seconds per day. For the remaining positions: each individual position value should not differ from the average of all five positions by more than 10 seconds per day.
Further demands are placed on the stability of the accuracy in each individual test position. The watch should not deviate by more than 5 seconds per day in any given position (at a constant temperature of 23°C). The mean of the deviations observed in the individual test positions should also be no greater than 2 seconds per day. Critical demands are also placed on the temperature dependency of the watch’s accuracy. The watch’s accuracy is tested within a temperature range of 8°C to 38°C. The deviation per degree Celsius and day should not exceed +/- 0.6 seconds. Finally there is a test to ensure that the watch regains its accuracy at 23°C, after the temperature change. In a given test position, the accuracy may not differ from the mean accuracy in this position measured before the temperature change by more than +/- 5 seconds per day.
In chronograph movements, the accuracy difference is checked with the stop function turned on and off. All accuracy measurements are carried out without the use of an electronic timing machine, i.e. the time is read off directly after 24 hours as measured on a test dial. The entire chronometer test takes a total of 15 days.
Up to now there has been no international standard (ISO) for quartz chronometers. In the meantime, the technical possibilities of series production have overtaken the requirements of the Swiss and German standard systems (see e.g. DIN standard 8319, part 2, from 1978). In 2001 the Swiss testing organization C.O.S.C. therefore formulated new criteria for its own testing practice. This placed more stringent requirements on quartz chronometer movements. The test criteria are designed so that quartz movements without special temperature compensation cannot pass the test. Based on these criteria, the daily average accuracy of a quartz chronometer should be between +/- 0.07 seconds per day at 23°C, and within a range of +/- 0.20 seconds per day at both 8°C and 38°C. The stability of the running accuracy at a set temperature is limited to 0.05 seconds. The test is conducted for a total of 12 days.
On account of its temperature compensation, a quartz chronometer is roughly twenty times more accurate than a high-quality quartz movement adjusted to room temperature, and represents the most accurate autonomously running wristwatch currently available. In our diving watches UX we use the thermocompensated ETA 955.652 movement with a quartz frequency of slightly over 32 kHz. Quartz movements with even higher running accuracy are technically possible in the form of megahertz oscillating quartz crystals, but only small numbers of them were made for a limited period due to the high manufacturing costs.
In our D3-System watches, the push-piece pins and crown shafts are mounted directly in a fine-finished case aperture, creating a perfect seal to the case.
In conventional designs, the push-piece pin and crown shaft are mounted in the case hole inside a tube insert. The required tube seal not only represents an additional potential source of gas diffusion (see Ar-Dehumidifying Technology), but careless handling can also lead to loss of water resistance with this design. This is because the push-piece pin and the crown shaft can bend in the tube if exposed to lateral knocks, permitting moisture to penetrate. This is a risk which also exists in screwable crowns and push-pieces when they are unscrewed to make an adjustment.
The D3-System permits the crown and push-piece to be integrated in the case, providing reliable protection from lateral knocks and the penetration of dust or moisture.
Sinn trademark: Used for watches featuring DIAPAL Technology.
A minute-clicking bezel which can only be rotated on one side to prevent accidental adjustment. It should also be possible to set a diver’s bezel when wearing gloves. Besides the main marking (e.g. luminous triangle) there may also be a minutes scale running clockwise.
diving equipment standard
Diving equipment, such as diving cylinders and breathing apparatus approved in accordance with European norms EN 250:2000 or EN14143:2003, is subjected to various tests to ensure that it functions correctly at low temperatures and in high humidity.
In 2006 Sinn commissioned Germanische Lloyd Hamburg to adapt these standards to wristwatches. Sinn’s diving watches were then for the first time formally accepted as integral pieces of diving equipment and tested as such.
The tests are repeated at regular intervals and the results documented as a means of ensuring consistently high quality.
Watches specially built for diving which, in compliance with DIN, have to fulfill a range of requirements in addition to being water- and pressure-resistant.
Sinn’s diving watches meet the safety requirements and pass the tests stipulated in DIN 8306. This contains the following test criteria:
• Fastening elements
• Air tight under high pressure
• Saltwater resistance
• Scale setting ring or diver’s bezel
• Functional reliability of control features
• Functional reliability of diving watch under high water pressure
• Resilience to temperature stress
• Perfect functioning of crowns, push-pieces and similar control features
• Watertight under high water pressure
Sinn attaches a great deal of importance to observing the prescribed requirements, and Sinn watches are often relied upon to withstand long-term professional use.
Name of sealing materials which have much greater diffusion-inhibiting properties than the conventional case sealing material (nitrile rubber, NBR). With these seals, the diffusion rate from inside the case to the air outside is reduced by up to 75 % in comparison to conventional nitrile seals.
EDR seal materials also offer further benefits. They are exceptionally weather and ageing-resistant and, in contrast to nitrile rubber, are not prone to ozone cracking. EDR seals are also resistant to numerous chemicals such as chlorinated, aromatic or aliphatic hydrocarbons.
The ageing processes in the movement depend largely on the microclimate in the case, meaning that EDR seals represent an effective Ar-Dehumidifying Technology component for ensuring greater accuracy over a longer period of time.
electronic timing machine
An instrument which measures a watch’s accuracy acoustically (i.e. from its ticking) and uses this to extrapolate the standard unit of seconds per day.
The isochronal error and amplitude can be read off directly. A timing machine will also break down the processes which occur in an individual beat, or oscillation, and show them in graphic form. The instrument can therefore be used for a range of diagnostic purposes.
The measured results of the watch’s rate, however, are always “snapshots” taken under laboratory conditions. For this reason, we also take each owner’s individual movements into account when making a specific regulator correction.
Thin layer of a perfluorinated plastic (e.g. Teflon) which is applied to certain parts of the escapement to prevent the watch oil from liquefying. An epilam coating is oil-repellent.
The part of a watch movement which periodically inhibits uncontrolled running of the tensioned gear train, thereby ensuring smooth running.
The escapement also supplies new energy to the oscillation system (hairspring), compensating the inevitable friction losses. Modern watches generally contain the Swiss anchor escapement (DIAPAL). This works on the principle of an anchor interacting with an escape wheel. The escape wheel intervenes directly in the seconds wheel, onto the shaft of which the seconds hand is fastened. The to-and-fro oscillation of the balance causes the anchor to rock back and forth. As a result it periodically intervenes with its ruby pallets in the escape wheel, blocking its rotation for a short period, before releasing it again for a short time (during the rocking motion). In one second, therefore, there are eight small steps of the seconds hand (at a half-oscillation rate of 28,800/h).
The Swiss anchor escapement is a proven design. However it requires lubrication to ensure proper functioning. Ageing of the oil is particularly apparent on the escapement. This is why SINN developed DIAPAL Technology. It permits the escapement to work without oil.
Electrolytic depositing of thin metallic layers for ornamental refinement of surfaces or for corrosion protection. During galvanising an electrically conductive workpiece (or one which has been made conductive) is coated with a thin layer of a different material. This takes place in a special immersion bath, using an electric current. Copper, nickel, silver or gold coatings are created electrolytically from the corresponding metallic salts (copper, nickel, silver salts). Sulphuric acid solutions of chromic acid anhydride are used, by contrast, to generate a shiny chrome finish.
If you dissolve a silver salt in water and pass an electrical current through the solution, the silver ions in the silver salt will migrate to the cathode (negative terminal) of the power source and be deposited there as neutral silver atoms (after being “reduced”). Objects being galvanised are therefore connected to the negative terminal of a power source, i.e. they are submersed as the cathode in the aqueous solution. The longer the treatment in the immersion bath is carried out, the thicker the galvanically created coating.
To keep the ion concentration at a constant level in the solution, an anode (positive terminal, or “target”) made from the coating material (e.g. silver) is used. It gradually dissolves during the galvanisation process and must therefore be replaced from time to time.
Conventionally created galvanic coats are relatively soft and are therefore susceptible to scratches and knocks. However there are other techniques which can be used to create gold plating with a surface hardness of up to 380 HV. We mainly use galvanically applied layers as means of refining dials and interior bezels. This method produces superior decorative brilliance in comparison to varnishing, and is distinguished by its exceptional UV colour fastness (ageing resistance).
Greenwich Mean Time. The astronomically defined local time in Greenwich which was adopted as world time.
GMT was established at the so-called “Meridian Conference” held on 1 October 1884 in Washington. On that day 25 countries agreed upon a binding time zone regulation to provide help to international shipping in particular. Ever since, the Earth has been divided into 24 time zones; adjacent zones differ by exactly one hour (apart from a few exceptional cases). The zero meridian runs through Greenwich (near London). This time zone was defined as the standard world time, GMT or Greenwich Mean Time.
The individual times were defined as astronomical local times, meaning that GMT, in contrast to UTC, is an astronomically based time. One second was defined as one 86400th of the mean solar day, and 12:00 o’clock noon as the sun’s highest point. Starting from zero, the meridians are numbered in ascending order to the east and the west, up to the 180° meridian. The 180th degree of longitude divides two days from one another, which is why it is also known as the dateline.
In practice, however, this theoretical zone division is not actually adhered to. Whereas Russia, for example, is divided into several time zones, China only uses one single zone although it stretches over roughly 60 degrees of longitude. The time zone in which a country lies, and how many time zones it covers, are also political decisions.
A spiral-shaped, coiled, flat wire which, together with the balance, forms the oscillation system of a mechanical wristwatch. Modern wristwatches generally contain flat coils with 12 to 15 windings, i.e. all the coils are in a single plane. In addition, most hairsprings are made of a metallic alloy called Nivarox.
The hairspring is fixed to the rotation axis of the balance and provides the decelerating and accelerating forces required to make the balance wheel oscillate evenly to and fro. The energy lost through friction is applied in pulses by the escapement.
Hairspring (here Breguet overcoil).
Hardness is a body’s resistance to penetration by another.
Hardness is measured using various methods based on different scales (Vickers, Rockwell etc.). The Mohs hardness scale was often used in the past for many purposes. However, it is very imprecise, as the entire hardness range is represented by values between 1 and 10. The most common methods used today are the Vickers, Rockwell and Brinell hardness test methods. All of these are penetration methods in which a small test object (e.g. a diamond pyramid) is pressed at a defined pressure into the test surface. The hardness can then be determined from the depth or the area of the resulting impression.
Sinn trademark. See Sinn Technology HYDRO.
Correction interval in quartz movements.
A range of different techniques has been used in different developments to optimize the accuracy of quartz movements. In the past manufacturers tried to produce the quartz as precisely as possible, to grind it or to set the precise oscillation frequency by depositing layers of vaporized gold and then removing it by laser. Today, quartz crystals are ground in such a way to produce a significant gain in the movement. This gain is then measured in each individual movement at room temperature. Subsequently the movement is programmed so that the gain is corrected every one to four minutes (depending on the caliber). The movement is briefly “paused” to compensate for the gain of the quartz oscillation.
In quartz chronometer movements there is also temperature compensation. The temperature sensor on the movement plate then helps to determine the current temperature in the watch and to calculate a correction value accordingly. The correction value which is applied once the inhibition cycle is complete is therefore not constant in quartz chronometer movements; rather it is continually adjusted in line with the current movement temperature.
Asymmetrical oscillation of the balance.
The rotary oscillation of a balance can be described as an angle of rotation. When the watch stops, the halted position of the balance defines its home position. A (constant) isochronal error is when the rotary oscillation is not executed entirely symmetrically around the home position in all test positions, i.e. the balance oscillates to different extents in each direction. This asymmetry can be made visible using a timing machine. Isochronal error is measured in milliseconds (ms). Sinn only permits a maximum isochronal error of 0.7 ms. High-quality watches possess a special device for adjusting the isochronal error.
low pressure resistant
The compression resistance of a water-resistant watch is always related to the increased external pressure that would be experienced in the form of a column of water pressing down onto the watch case, whereas high-altitude resistance is related to reduced external pressure as encountered at high altitude above sea level. If the pressure outside the watch case falls, the difference between the pressure inside and outside the case acts as a force pushing from the inside out. Special design features have to be incorporated to ensure that the glass cannot escape from its press fit.
A coating for watch dials and hands, enabling them to be read in the dark.
In the past the main luminous paint used was radioactive tritium (3H). Today inactive luminous paints such as Superluminova are used almost exclusively. These are charged by the incidence of light and exhibit a temporary luminous effect (phosphorescence). Daylight luminous paints are used in individual cases (e.g. NaBo).
Magnetic Field Protection
Watch case which shields against magnetic fields. See Sinn Technology Magnetic Field Protection.
Forces which can commonly be observed in the form of magnetized objects attracting and repelling each other. Possible source of interference in a watch s action.
Magnetic fields are encountered with ever-increasing frequency in our environment. Whereas the Earth’s magnetic field does not constitute a risk, magnetic fields from loudspeakers, door closers, locks etc. can have a lasting effect on the action of a mechanical watch. In a survey of almost 1000 watches carried out by SINN’s customer service department, roughly 60% of these proved to be magnetized, and half of these, i.e. 30% of the total, exhibited strong magnetic field errors. In some cases the accuracy errors could be corrected by demagnetizing them.
For this reason we are now equipping increasing numbers of watches with our Magnetic Field Protection Technology.
The main source of magnetic field errors lies in a magnetized Nivarox hairspring, i.e. the timing organ of the watch. Nivarox hairsprings are far superior to older steel springs with regard to magnetic field sensitivity, as Nivarox springs are antimagnetic (DIN 8309). However this requirement permits an error margin of +/- 30 seconds per day under exposure to relatively weak magnetic fields. This, though, is not compatible with chronometer standards.
Mission Timers are watches which have been specially developed for a particular purpose. They always offer excellent readability. This means: the form is always dictated by the function and handling requirements.
The legendary EZM1 was the first in a successful line of mission timers.
Mohs Hardness Scale
Relative scratch resistance scale, devised by mineralogist Friedrich Mohs (1773 to 1839).
The Mohs hardness scale is a relative hardness scale from 1 to 10. It was specially devised to rate minerals. The scale is based on the following principle: if two minerals cannot scratch each other, they are both said to have the same hardness. If a mineral cannot be scratched by one mineral on the scale, but can be scratched by the next hardest mineral, then its Mohs hardness lies between the two hardness figures of the relevant minerals. At one end of the scale is diamond, with a value of 10, and at the other end is talcum.
The Mohs hardness scale is imprecise and non-linear in comparison to the Vickers scale. The difference in hardnessbetween corundum and diamond is up to 8000 Vickers. On the Mohs hardness scale, however, the difference in hardness carries a value of one. By contrast, minerals with Vickers hardness levels which are much closer together, such as quartz and corundum, are separated by two points on the Mohs scale.
For this reason the Mohs hardness scale is not used for material specifications. It is, however, a useful tool for classifying minerals.
Sinn trademark, standing for navigation cockpit clocks. Navigation cockpit clocks are intended for installation in aircraft cockpits.
Chemical element: a hard, silver-white metal obtained primarily from magnetic pyrites.
Nickel is an important alloy component in many types of steel. The nickel content in these is between 9 and 18%. Nickel steel is exceptionally hard and robust. It is used for tools and for military purposes (armor plate, gun barrels). Combined with chromium it produces highly corrosion-resistant chromium-nickel steel. Some people have an allergic reaction to it if it comes in contact with their skin.
nickel-free metals and nickel release
Nickel release is basically a measure of the release of nickel into the skin. The emission of nickel can result in allergic reactions. The standard stipulates that no more than 0.5 µg of nickel may be released per square centimeter of skin per week. This limit may not be exceeded by any product coming into direct and long-term contact with the skin.
The level of nickel release is not determined by the nickel content of a metal, rather by its corrosion resistance. Only through corrosion processes can nickel escape from a steel alloy in the form of ions or complexes. In highly corrosion-resistant steel, the nickel therefore remains stably bonded in the steel even if it has a relatively high nickel content. For example, stainless steel containing nickel (content 12.5% to 15%) is used even in medical implants, without any allergic reactions being observed. At Sinn we also use this same grade of steel (DIN 1.4435). Its nickel release is 50 times lower than the value prescribed by EURO standard 1811. This corresponds to 2%.
There are also grades of steel with a residual nickel content of less than 0.2%. This, however, is merely the impurity traces of nickel measurable in all types of stainless steel and not an alloy component. In this case and also in the case of special case backs offered by Sinn, we therefore refer to nickel-free steel although strictly speaking it is non-nickel-alloyed steel.
Metallic alloy used to make superfine hairsprings.
This alloy solves to a great extent the problem of temperature-related changes to the elasticity and length of the hairspring and the balance. As the temperature rises, a metallic spring generally becomes softer and longer; the diameter of a metallic ring (balance) also increases slightly. However, such a change in the material characteristics would cause the balance to oscillate more slowly, and therefore the watch to lose time. Nivarox is the name (derived from the German terms for “non-variable” and “oxide-resistant”) of the most common type of alloy used to make temperature-compensating (or auto-compensating) hairsprings. This material solves the problem of temperature sensitivity in two ways. Firstly a Nivarox spring only changes its length and elasticity to a relatively small extent within the temperature range stipulated by the chronometer norms. Secondly, the remaining temperature effect is compensated by processes inside the spring itself (hence the term “auto-compensating”). These compensatory processes stem from the magneto-strictive properties of nickel – an element which appears in Nivarox springs as an alloy component.
Magneto-strictive interaction takes place in certain conditions in (ferro-) magnetic objects. Such objects have an internal magnetic field structure which is not necessarily apparent as an external magnetic field, as the internal fields of the magnetic domains (Weiss domains) cancel each other out. The objects are therefore in a constant state of internal magnetization. What is decisive is that the predominant magnetic field structure depends on the temperature of the object and that a change in this structure due to magneto-strictive interaction causes elastic tension in the object, i.e. deforms it, which then neutralizes this tension.
This link between elastic tension and a magnetic field is also known as magneto-striction. Two aspects are important here: Firstly a change in temperature, as explained, always has the effect of altering the magnetization status and therefore the internal tension of the spring. Secondly, the direction of the magneto-strictive effect is the exact opposite of the temperature response of ordinary materials.
This means that, as the temperature rises, the magneto-strictive interaction causes the spring to harden and shorten. In watches with Nivarox coil springs, these two factors combined cause the rate of the balance system to remain largely constant despite any change in temperature. If the temperature does rise, two effects cancel each other out to a certain extent: the magneto-strictive hardening and shortening of the spring counteracts the usual temperature-related slackening and extension of the spring and the increased inertia of the balance wheel.
A Nivarox I coil in combination with a glucydur balance therefore yields a (primary) temperature error of less than half a second per degree Celsius per day.
However, the basic principle of this temperature compensation – the use of ferromagnetic materials – leads to susceptibility to external magnetic field influences, as other magnetic fields can of course change the magnetization status of the spring, and hence its elasticity, in addition to the temperature. This can cause considerable rate deviations up to and including complete stoppage of the watch (see magnetism).
Unsusceptible to the influence of magnetic fields up to a defined strength.
Strictly speaking, no material is completely unaffected by magnetic fields. Materials or objects are described as non-magnetic if they react so minimally to magnetic fields that sensitive instruments are needed in order to detect any effect. For all practical purposes, materials such as glass or some types of steel can be rated non-magnetic.
The 24-hour pointer, shaped in the form of an arrow, is intended to help calculate the compass direction.
When the current position of the sun is visible, a 24-hour pointer, which runs synchronously with the 12-hour hand, makes it easier to determine the approximate direction. In the Northern hemisphere, if the dial is oriented horizontally and the watch turned so that the 12-hour hand (ignoring daylight savings time!) points to the sun, then the 24-hour pointer will point North. In the Southern hemisphere, North and South should be exchanged.
It should be borne in mind that, depending on the time of year and the parallel and meridian, the calculated geographical North may deviate by up to 25°.
The Sinn 900, 6060, U2, 856 and 857 models are fitted with such a pointer combination.
Decoratively refined movement, e.g. featuring ornamental grinding, mirror finish, engraving, galvanic surface refinement or special components.
Regardless of its technical design quality, the aesthetic appeal of any movement can be enhanced through various decorative features. Bridges and plates offer scope for engraving or skeletonisation and can also be given ornamental grinding features (e.g. sun, stripes or clouds).
Instead of conventional nickel-plating of the brass bridges and plates, a galvanic rhodium coating (a metal from the platinum group) or a colouring metal compound can be applied. Screw heads can be polished, varnished blue or turned blue through tempering. Simple edges can be transformed through angling (to create a chamfer). Milled ring grooves around visible bearing jewels create the impression of a bearing lining (Chaton) in places where the gold-coloured substrate is exposed in a rhodium-plated bridge.
In contrast to a diving watch, there is no binding definition of the term “pilot watch”. It often refers merely to a certain kind of traditional dial design. Additional features such as a pilot’s bezel, stop-watch function and slide-rule bezel may also be integrated. It should always be possible to adjust pilot’s scale in both directions.
Our pilot watches always offer maximum readability. In addition, all SINN pilot watches must be capable of withstanding negative pressure of up to 0.2 bar. This corresponds to a flying altitude of approx. 12,000 m.
Special requirements for pilot watches had never been identified and formulated before, and so in 2008 SINN launched a project with the Department of Aerospace Technology at the Aachen University of Applied Sciences aimed at determining these technical and functional requirements, using these as the basis for establishing the optimum features in a pilot watch.
A bezel which can usually be rotated in both directions, in some cases with minute clicks.
Besides the main marking, a clockwise or counter-clockwise (“count-down”) minutes scale may also be featured. It should be possible to operate a pilot’s bezel when wearing gloves.
According to DIN, the pressure resistance of a water-resistant watch describes the pressure load which a watch can withstand.
PVD (Physical Vapour Deposition) refers to a group of processes used to apply thin layers of hard material to an object. The coating material is initially provided as a solid. It is then vaporized or atomized and subsequently deposited on the substrate, with no change to its chemical composition. The main advantage of PVD lies in their relatively low deposition temperatures. This permits a wide range of materials to be used for coating.
The surface hardness of PVD coats is 2000 to 3000 HV, depending on the type of coating. It is therefore significantly higher than that of galvanically applied chrome plating. The possible coat thicknesses start at the nanometer level and can be built up to several micrometers.
A negative effect arises if such thin hard material coats are applied to untempered materials such as stainless steel or titanium (180 to 220 HV). Knocks and scratches give rise to the so-called eggshell effect on account of the difference in hardness between the hard material coat and the base material. The coating collapses, exposing the different color of the material beneath.
At Sinn we only use hard material coats in combination with TEGIMENT for this reason. TEGIMENT has a hardness of approx. 1200 HV and merges gradually, and not suddenly, into the hardness of the case stainless steel itself. This avoids the eggshell effect.
The stages involved in achieving that highest possible degree of accuracy in a watch.
Even though the production quality of toothed wheels, bearings and pivots is decisive for the stable running of a watch, these manufacturing stages are not generally regarded as part of the regulation system.
However, the regulator correction at the end of the regulation process, which is often the most visible aspect of regulation, can only succeed as part of a good overall regulation process.
Regulation can cover both the different test positions and also temperatures. This is required in particular in the regulation of a chronometer.
regulator D regulator correction
A device used to set the rate of a watch.
Regulator device mounted on balance cock.
A regulator correction changes the effective spring length of the oscillation system’s hairspring. Before the hairspring hits its outer fixture point it passes through a gap formed by two adjacent pins. The part of the spring between the gap and the outer fixture point is exempted from the free oscillation of the spring. If the position of the gap is shifted by a regulator correction, this changes the active spring length. Depending on the direction of the change, the watch then runs faster or slower.
Watch glass made from artificially produced sapphire crystal. Sapphire crystal consists of monocrystalline aluminum oxide (Al2O3). At 2000 HV on the Vickers hardness scale, it is a scratch-resistant watch glass. It is also considerably more scratch-resistant than mineral glass.
sapphire crystal, domed
A specialty of high-quality watchmaking.
On account of its exceptional hardness, sapphire crystal is the material of choice for high quality watch glasses. Watch glass made of sapphire crystal is significantly more difficult to manufacture than mineral or synthetic glass.
A total of up to five different radii of curvature are created for our domed sapphire crystals by means of elaborate cutting and grinding processes – a special feature which is contrasted here briefly with conventional glass forms.
The final form of flat sapphire crystal is not too different from that of its original raw state. These watch glasses can be cut directly from a cylinder and then polished.
Section through flat sapphire crystal.
The blank of a single-dome sapphire crystal watch glass needs to be thicker than the final glass thickness. However, the final shape of the crystal is only formed from a single dome radius, meaning that the grinding process is still relatively simple.
Section through domed sapphire crystal.
A domed sapphire crystal watch glass for model 356 recreates the form of the acrylic glass, using five different curvature radii. For this reason, grinding tools which have been specially made for the specified radii are needed to create the inner and outer form of the dome.
The domed sapphire crystal watch glass of model 356.
The thickness of the sapphire crystal glass blank for our 356 model is roughly 5 mm, i.e. it is much thicker than the blank for a conventional flat glass. The final shape must first be ground out of this blank and then carefully polished.
Blank for sapphire crystal glass with indication of final watch glass.
Watches which are shock resistance must meet the requirements set out in DIN 8308. The testing equipment must deliver a hammer blow at a speed of 4.43 m/s. The resulting change in the watch rate should not exceed +/- 60 seconds per day. The speed of 4.43 m/s is derived from the previous requirement that a fall from a height of 1 m onto a wooden floor should not result in any defect in the movement. All Sinn watches are shock resistance as defined by DIN 8308.
Sinn sealing grease 30-288
Fully synthetic grease developed especially for SINN for use on seal rings at temperatures ranging between -45°C and +80°C. A seal ring treated with this grease has a considerably lower gas permeability rate than an ungreased ring at the same compression and temperature. It also increases the ageing resistance of the seals.
The performance of EDR seals is optimized through the use of Sinn sealing grease 30-288. This combination gives Sinn watches significantly greater protection against humidity than any conventionally sealed watch.
Sinn special oil 66-228
High-grade, fully synthetic oil specially developed for Sinn. Its outstanding properties at low and high temperatures allow the watch to run accurately from -45°C to +80°C.
The slide-rule scale works on the principle of logarithmic scale divisions. This allows you to multiply and divide numbers. It is useful for calculating consumption, converting units and currencies and for all kinds of rule-of-three calculations.
Stainless steel is a grade of steel with a very high degree of purity and a chemical composition defined within narrow tolerances.
Of particular importance in watchmaking are corrosion-resistant stainless steels, i.e. types of steel which are protected from corrosion.
Special grade of steel developed by ThyssenKrupp for the outer shells of the very latest non-nuclear submarines, the 212 class, of the German navy.
Sinn’s U series diving watches are made entirely from this special grade of steel.
This material is 100% austenic steel; it is exceptionally strong and has superior non-magnetic properties. Its mechanical strength is more than 1.55 times that of the usual watch case steel AISI 316L.
A further advantage of using this steel in the manufacture of diving watches lies in its unique saltwater resistance. Normal case steel has to be rinsed in fresh water after contact with saltwater, as long-term exposure to saltwater can, in adverse circumstances, lead to corrosion. Submarine steel, by contrast, is completely resistant to prolonged contact with saltwater. Also, submarine steel is, on account of its ductility, extremely resistant to cracking, thereby further increasing its reliability.
Submarine steel can also achieve hardness levels of up to 1500 HV (Vickers hardness) thanks to our TEGIMENT Technology. This value surpasses the hardness of standard case steel with TEGIMENT Technology by roughly 300 HV, further raising the scratch resistance.
Acronym for SÄCHSISCHE UHREN-TECHNOLOGIE GMBH GLASHÜTTE.
SUG is a manufacturer of high-grade watch cases. In 2001 SUG was the first, and to date the only, German watch case manufacturer to be awarded DIN EN ISO 9002 certification.
This standard requires exacting quality management based on the use of suitable test methods and full traceability of all procured materials.
Most of the outstanding watch cases made for Sinn are manufactured by SUG in Glashütte in Saxony and carry the SUG inscription.
Luminous paint for dials and hands, belonging to the group of inactive luminous paints, i.e. it emits no radiation. The luminous effect is based on the principle of phosphorescence.
Superluminova therefore needs to be charged by an external light source. In order to exploit the maximum luminous capacity of the paint pigments, the paint must first be fully activated. In direct sunlight this takes roughly 90 minutes. Superluminova can be charged and discharged as often as required without losing any of its charging capacity. A further advantage in comparison to tritium-based radioluminescent paint is that it does not turn gray or yellow with age.
The SZ01 chronograph is based on the successful Valjoux 7750 and has been specially developed by SINN. The development work began back in 2003.
Schematic diagram showing chronograph functions of the SZ01.
The main priority in undertaking the redesign was to make the chronograph functions significantly easier to read off. Which is why we attached so much importance to finding a first-class technical solution to mounting the stopwatch minute hand in the centre of the dial. This allows users to take accurate stop times even more quickly and simply. The clarity and distinct readability of this chronograph stem from the design of the well-known Lemania 5100 movement.
Our redesign enhances the readability in two ways: firstly, 60 minutes are now counted in one sweep of the hand instead of the usual 30 minutes, and secondly, the minute stop scale covers the entire diameter of the dial.
Chronograph developed by Sinn on the basis of the Valjoux 7750.
The Valjoux 7750, by contrast, only has a 30-minute chronometer counter. Stopped times are difficult to see on this standard caliber as the interim marks of the hour counter are very close to the hour indices. Only with the aid of this pointer is it possible to distinguish between a minute display of 0 to 30 and 30 to 60. The SZ02 permits direct reading of the minutes right through from 0 to 60 minutes, meaning that the hour counter only needs to be read in terms of full hours.
The SZ02 was launched in 2006, the year of the World Cup in Germany. It was housed in the case of the 303 football chronograph. The caliber has more than proved its worth since then, forming a reliable base for the perfect readability of the diving watch U1000 range.
Sinn’s own rebuild of the Unitas 6498 pocket watch caliber into a movement with regulator display.
A regulator pointer recalls a feature found in precision grandfather clocks, which have a large-diameter fine-minutes dial for regulatory or monitoring purposes. For reasons of better readability in the minute hand, this features small, off-center hour and second dials.
Sinn has moved the hour dial from the center towards 12 o’clock, without causing any additional friction losses or using additional gearing. The Unitas 6498 caliber already had a small seconds dial, and the SZ04 represents the optimum horological solution of a regulator display with three separately positioned dials for hours, minutes and seconds.
Sinn’s own rebuild of the Valjoux 7750 watch caliber.
The objective of this design innovation was to considerably improve the legibility and clarity of the dial displays. To this end, in designing the SZ05 we focused on a stopwatch minute display with a 60-minute scale at 3 o’clock and a running second hand at 9 o’clock. This does away with the annoying necessity of adding the stop minutes as required with conventional 30-minute stopwatch displays.
The tachymeter scale permits an average speed to be measured over a distance of one kilometer. For this, the stop-watch function must be activated at the start and end of the distance. Miles per hour (mph) can also be measured using the tachymeter scale and the same principle.
Sinn technology: metal with a hardened surface. See Sinn Technology TEGIMENT.
Temperature compensation refers to devices or combinations of materials which keep temperature-related fluctuations to a minimum.
The physical timer processes at the heart of a timepiece movement are subject to temperature fluctuations. For example, when warm, the pendulum of a large clock becomes elongated, extending the duration of the oscillation. The rotational oscillation of a balance also changes its frequency due to temperature fluctuations, as the length of the hairspring, the circumference of the balance wheel and the elasticity of the spring are all temperature-sensitive.
In the past, bi-metallic designs were common in pendulums and also in balance wheels. Two metals with different thermal expansion coefficients were combined so that two contradictory expansion effects cancelled each other out in temperature fluctuations.
In modern mechanical wristwatches, the temperature is compensated by the use of springs made from Nivarox. By contrast, a temperature sensor is used in high-quality quartz chronometers (see chronometer quality, such as the models in the UX series. The correction value of the quartz oscillation is constantly adjusted in its inhibition cycle in line with the measured temperature.
Temperature Resistance Technology
See Sinn Technology Temperature Resistance Technology.
Sinn only uses titanium grade 2 and titanium grade 5, which is an ideal material for wristwatches.
No allergic reactions are known. With a specific weight of roughly 4.5 g/ccm it has just 60% of the weight of stainless steel (specific weight approximately 7.8 g/ccm). It quickly absorbs body heat as a result of its low specific thermal capacity and its low thermal conductivity. This makes it comfortable to wear, particularly during the cold months of the year. The low electrical conductivity of titanium also increases wearing comfort as it reduces the electrical voltage compensation between different parts of the skin around the wrist.
Grade 2 titanium: pure titanium with the material number 3.7035.
Grade 5 titanium: a high-strength titanium alloy with the material number 3.7165.
A radioactive luminous paint for dials and hands.
Tritium is an isotope of hydrogen (3H), a volatile gas. It is slightly radioactive and has a half-life of 12.3 years.
Luminous paint which is energised by tritium does not need to be charged by external light. The volatile gas is bonded in a polymer (tritiated plastic). With its electron radiation, it energises a passive luminous substance such as zinc sulphide, causing it to emit visible light.
The radioactivity emanating from the tritium coating in a water-resistant watch covered with a sapphire crystal is not detectable. Luminous paints containing radioactive tritium are completely harmless to wearers of watches.
Universal Time Coordinated (UTC) = coordinated world time, since 1975 (15th General Conference on Weights and Measures) the basis both for legal time and also for scientific-technical applications in astronomy, navigation and electronic communication.
The UTC scale is not an astronomically based time, rather it is calculated from the coordination of roughly 250 atomic clocks worldwide. The irregular rotation of the Earth results in small discrepancies to GMT using this definition.
However, reference to the mean solar time at 0 degrees longitude is necessary for navigation purposes, and so UTC is adjusted to the astronomically anchored GMT by means of leap seconds. This adjustment is made once per year if the deviation between the two times has grown to more than 0.9 seconds.
Central European Time (CET) is UTC plus one (or two) hours (daylight savings time).
A very commonly used indication of the hardness of a material. The associated measurement process prescribes pushing a small diamond pyramid into the test object at different test loads. The diagonal of the resulting impression is measured and an average obtained. This is used to calculate the hardness.
Stainless steel: approx. 200 up to 240 HV
Titanium: approx. 210 HV
Hardened mineral glass: approx. 800 up to 900 HV
TEGIMENT: approx. 1,200 up to 1,500 HV
Hard metals: approx. 1,350 HV
Sapphire crystal: approx. 2,000 HV
Diamond: 4,500 HV up to 10,000 HV
If a Sinn watch is labeled water-resistant, it fulfils the requirements of DIN 8310 in its original specifications. Sinn guarantees that its water-resistant watches can withstand pressures up to at least 10 bar. This corresponds to the pressure at a depth of 100 m. Some of our classic masterpiece models are exempt from this. The water-resistance of each individual watch we produce is checked. The maximum depth given on many watches always refers to the maximum static compressive stress which the watch case is guaranteed to withstand. When swimming, or in a jet of water (washing hands or showering), there are also directional flows with dynamic pressure peaks which impact upon the relevant parts of a watch to a greater extent than the diving depth alone.
In order to use a watch safely when swimming we therefore recommend a compression resistance of at least 100 m. Diving watches are recommended for intensive and frequent use in water. The compressive resistance of a diving watch is given in bar or in depth, measured in meters. When diving, the pressure increases by one bar every 10 m.
In everyday use it is important to note that seals can suffer from wear or ageing and that small direct particles can build up in them as the result of a wide range of factors which arise when wearing a wristwatch. These particles can themselves assume a part of the seal function if the seal elements are already suffering from extensive wear. Tensides from detergents or similar cleaning agents can then coat such particles, making it easy from them to be washed away.
For these reasons the airtightness of a wristwatch should be checked on a regular basis (once per year).
Gold alloys are not restricted to gold tones, they also come in a range of colours. By changing the proportions of copper and silver, a gold alloy can be given a yellow, rosé or reddish appearance. An additional alloy component is required to produce high-carat white gold which bleaches the gold evenly to make it look like steel or silver. In the past, nickel was used for this. However, palladium is now used on account of the growing allergy problems and the resultant Euro standard 1811 which has set a legal restriction on the release of nickel in jewellery in direct contact with the skin since the year 2000. Palladium, though, is a very expensive precious metal, and companies often like to save costs by treating the surface of their jewellery products with a galvanic rhodium coating. This coat covers the remaining yellow colour of the base material and also protects it from tarnishing.
We use an 18ct gold alloy containing a high proportion of palladium. As a result, the alloy does not need to be coated with rhodium to alter the colour tone.