What you should know about Watches
Why you should buy your watch from a member of the Jewellers and Watchmakers of New Zealand Incorporated (JWNZ).
- Knowledge of the watch industry requires years of study. Therefore, it is vital that you buy your watch from a reputable jeweller or watchmaker.
- Established jewellers and watchmakers prize their good reputation.
- It is important to know the company you are dealing with. Ask questions. Be confident of returning for advice and service in the future.
- A JWNZ jeweller or watchmaker can explain the different types of watches available and advise on watch care and handling.
- You can be assured of professional service and specialist, honest advice.
The old saying "you only get what you pay for" is very applicable in the watch and clock industry. Therefore, before buying a watch it is important to know the characteristics and advantages of each brand, as well as the benefits of the more expensive model. A basic knowledge of the features of the product will help you make your choice. These may include time, date, month, alarm, stopwatch, lap counters, memery recall, dual time zone, wourl time, duo display etc. Mechanical watches are usually associated with tradition, technical know-how, emotion and prestige. Analogue and digital quartz watches are usually associated with precision, reliability, price and compact case size.
Why can similar looking watches vary so much in price?
Sometimes watches can look similar, but one is of superior construction (steel case vs chrome or brass etc) and some expensive brands may have a large promotional content. Your JWNZ member can usually advise on the best value for money watch.
The most common are: Chrome plated – used for economic reasons on less expensive watches. Gold plated – electroplated a few thousandths of a millimetre thick of pure gold over a base material or steel. Plastic – very popular for both sports and coloured fashion watches providing a light weight, durable, low cost alternative to metal cases. Stainless steel – a practical and durable material. When shaped into a water resistant case it provides maximum protection for the movement so that the watch achieves maximum longevity. Titanium is an alternative material, being very light, strong and completely non-allergenic. Check either the back of the case or the documents accompanying the watch for disclosure of metallic content.
Type of movement, accuracy and reliability
Regardless of the materials used in any watch, accuracy and reliability are the two most important elements to bear in mind when choosing a watch.
What is the main difference between mechanical and quartz watches? Accuracy. The accuracy of mechanical watches is measured in so many seconds per day, but that of quartz watches is measured in so many seconds per month or per year. Quartz watches use quartz as the source of oscillation, instead of a mechanical balance wheel. The accurate signal generated is converted into a mechanical revolution by a step motor to turn the hands.
Can extreme temperatures upset accuracy? Heat and cold can affect the precision of both mechanical and quartz watches. Oscillation of the quartz oscillator varies according to temperature and this does affect the accuracy of the quartz watch very slightly. But this change is very small compared to the effect of temperature on mechanical watches where the consistency of the lubricant influences accuracy.
What else determines accuracy? Consistency is the key with mechanical watches. Accurate time telling can be enhanced by winding the watch at a certain time every day, wearing the watch for a certain period every day and the way a watch is left lying when it is not on the wrist. Quartz watches are pretty trouble free – temperature extremes are the only variable here.
What is the life of a quartz watch battery? Watches are designed to use either silver oxide or lithium batteries. A silver oxide battery will last two-five years. Lithium batteries have a life of two-seven years depending on the use of the watch functions, for example, the light and alarm which use a much larger current than that which activates the watch itself.
Can I wear my watch while playing sport? Modern mechanical watches are equipped with anti-shock devices that protect vulnerable parts, however, a really hard knock can cause harm. Quartz and Digital Watches are usually designed to be shock resistent, but care should be taken to avoid dropping or striking the watch on hard surfaces.
Where do I take my watch to be serviced or repaired? You can assured of professional service from a member of the JWNZ. If you have special requirements, for example, regarding the water resistancy of your watch please discuss this with your jeweller or watchmaker before the service. Also check if your watch is still covered by its guarantee.
What happens during the overhaul or complete service? The watch is dismantled and the case and bracelet are cleaned and polished. After the movement parts are cleaned by chemical means, a close inspection reveals if any parts need to be replaced. The movement is reassembled and lubricated and adjusted if appropriate. The watch’s water resistancy is also tested if appropriate.
Do I need to take my quartz analogue watch to be serviced as often as a mechanical one? Quartz watches usually need less maintenance because they do not have as many moving parts. They generally need to be serviced when they stop or lose time and the battery is not the problem.
Types of glass
A glass or watch crystal is the transparent cover that protects the watch face. It is made of either acrylic, "mineral" glass, or sapphire crystal. Some crystals are made of both mineral and sapphire glass, covered with a layer of synthetic sapphire.
Which watch crystal is best? Acrylic is the cheaper option – it is break resistant, but scratches relatively easily. Mineral glass is more scratch resistant than acrylic but, because is a harder material it is more likely to shatter. The more expensive sapphire glass is the most scratch resistant and is second in hardness only to a diamond.
Genuine leather or synthetic, nylon, rubber or plastic, metal plated, stainless steel, Kevlar and polyurethane ... natural or man-made, the choice is endless. Thanks to new technology many materials offer improved durability and antiallergenic qualities, as well as the latest in fashion and colour. Band types can influence watch prices considerably. Leather and exotic skins can range from $10 to hundreds of dollars. Similarly metal bracelets can range from inexpensive base metals to precious metals, to specially-developed tungsten carbide or titanium.
According to current valid standards, a wristwatch may be termed "water resistant" if it is able to withstand perspiration, water drops or rain. It is not suitable for swimming. Higher resistance values are usually indicated on the dial or case, for example, in the form of the test pressure in bar or in metres.
What features make a watch water resistant? The watch’s most important property is the gaskets or O rings, made of rubber, nylon or Teflon, which form watertight seals at the joints where the crystal, case back and crown meet the watch case. Another factor to consider is the sturdiness of the case, which must withstand pressure without distorting. A steel or titanium case or a steel case plated with gold can be worn safely underwater. Gaskets are also lined with a sealant to keep water out. A screw-in case back is also preferable to one that is pushed in.
Should I take water resistance for granted? No. All water resistant watches should have their water resistance checked every time the battery is changed or the case is opened and the gaskets dislodged. That’s why it is important to take your watch to a repair centre with water resistance testing equipment. If you wear your watch often while swimming or expose it to a lot of sweat, it should be checked at least every two years.
How is water resistance tested? Two methods are used – "dry" testing using air pressure measurements to see if the case expands as a result of air leaking into the case – if it doesn’t the watch is water resistant.
"Wet" testing – the watch is subjected to air pressure, then submerged in water. Emerging air bubbles will point to air seepage into the watch before it was submerged.
MARKING RECOMMENDED USAGE
(International Standard ISO 2281)
- WATER RESISTANT Suitable for everyday use. Splash/rain resistant. NOT suitable for swimming.
- 5 BAR 50 METRES Suitable for water related work, recreational swimming & fishing. NOT suitable for diving.
- 10/15 BAR,100/150 METRES Suitable for recreational surfing snorkelling, sailing & water sports. NOT suitable for diving.
- 20 BAR 200 METRES Suitable for professional marine activity & serious surface water sports. NOT suitable for diving.
(International Standard ISO 6425)
- DIVERS 200 METRES Scuba diving at depths NOT requiring helium gas.
- DIVERS 300 METRES requiring helium gas and over Deep sea diving at depths (Dealer’s advice should be sought)
This guide has been developed by the Jewellers and Watchmakers of New Zealand (Inc.) in conjunction with the major watch importers and wholesalers in New Zealand.
In time, the seals on your watch may deteriorate. We recommend that you have the water-resistance of your watch checked once a year by a watchmaker who will replace the seals if necessary.
The Jewellers and Watchmakers do not recommend using any watch whilst in the shower, spa or hot pool.
How permanent is water resistance?
Any manipulation of the case or ageing of the sealing material may allow water to penetrate even cases with good water resistance. Gaskets can become corroded by chemicals or crystals loosened or broken. Hairsprays, perfume sprays and heavily chlorinated water can also cause damage.
Your guarantee covers defects in material and workmanship for a certain period from the date of purchase. When purchasing your watch make sure the conditions of the guarantee are explained and the appropriate form is filled in by the vendor. Well-known brands often come with an international guarantee. When buying your watch in New Zealand your purchase is also covered by the Consumer Guarantees Act. Keep your guarantee in a safe place.