Multi Tester Instructions Multi Tester Introduction The Multi Tester uses thermal conductivity to test for diamond. Moissanite (a man-made stone) has the same thermal conductivity as diamond and registers as diamond on diamond testers, and so for Moissanite the Multi Tester measures electrical conductivity. The UV light is to give more accurate readings on Moissanite (it excites the atoms and improves electrical conductivity) and can also be used to observe the fluorescence in diamonds for the purpose of colour grading. Other features: tests stones mounted in jewellery or loose stones (stone-holder included); built-in metal alert (alarm sounds if you accidentally touch the setting); fully automatic, requires no calibration by the user; powered by one standard 9v battery; alarm sounds after a few minutes if the power is accidentally left on. There is the option of using an AC power supply (not included). There is also a new, patented, feature: the Multi Tester is fitted with an illuminating ring around the probe which lights up in different colours to correspond with the test result, and with each colour it makes a different sound. This allows the user to see the result without having to watch the lights on the top of the tester. Page 1
Components of the Multi Tester Wait Light Amber Metal Alert Light Blue Diamond Alert Light Green Moissinate Alert Light Probe Cover Ready Light Touch-Plate On / Off Switch UV Light Switch Power Socket Testing Probe Tip 360 Degree Illuminating Ring Battery Conection Lead Battery Cover UV Light Page 2
POWER The Multi Tester takes one 9 volt PP3 battery. Use only a good quality alkaline battery, Duracell and UCAR are good makes. Ordinary Super or High Power batteries may not be suitable. A good quality battery will give 2½ hours of continuous use (or 5 hours without using the UV light). A poor quality battery will last five or ten minutes. Slide the battery cover open in the direction of the arrow; insert the 9v battery into the tester taking care not to catch the wire in the battery cover when sliding the battery cover back on. If accidentally left on, a continuous alarm will sound after a few minutes. When the WAIT light flashes the battery is low, change the battery. If the Multi Tester is not going to be used for several weeks, remove the battery. The Multi Tester can also take a mains-powered adaptor (not supplied). The specifications are 9v DC 0.5A. (center negative). Using an incorrect power supply can damage the Multi Tester beyond repair. Page 3
INSTRUCTIONS 1) 2) 3) Page 4
INSTRUCTIONS 1) Switch the Multi Tester on. It will take about 45 seconds to warm up, so while you are waiting, clean the stone. Clean the top (table) of the stone thoroughly using an alcohol such as isopropyl. If you don t have any isopropyl, use any alcohol. Apply with a tissue or cotton wool bud and wait a few seconds for it to dry. The slightest amount of grease will give false readings on Moissanite. 2) Turn on the UV light. Hold the Multi Tester so that your index finger is touching one of the metal touch-plates and your thumb is touching the other, ensuring that you have made firm contact. Do not touch the top of the Multi Tester. Note from the pictures how to hold the tester correctly and how NOT to hold it. 3) When the READY light shows, press the probe tip onto the top of the stone firmly (but not so hard that you bend or break the tip) and wait for the result. You should not have to wait more than five seconds for a result. Caution - too much force may break or bend the probe tip, which is not covered by the guarantee! Testing the same stone two or three times in succession will make it warm, and a warm diamond will no longer register diamond, so wait two or three minutes between tests to allow the stone to cool down. The ideal temperature for use is between 15 C and 27 C, and the ideal humidity between 45% and 75%. This tester cannot, therefore, be used outside in the cold and damp, or in direct sunlight in a heat wave. Page 5
THE READINGS 1) Diamond = Blue 2) Moissanite = Green 3) Metal alert = Amber LIGHTS ON TOP SOUND LIGHT AROUND PROBE DIAMOND Blue Diamond light Quick beeping Beep..beep..beep..beep Blue MOSSANITE Green Moissanite light Slow beeping Beep beep beep Green METAL ALERT Amber Metal light Continuous beep Beeeeeeeeeeeeeeep Amber ANY OTHER GEMSTONE No lights No sound No lights Page 6
GETTING THE BEST OUT OF YOUR MULTI TESTER Diamond testing (thermal conductivity) The tip of the tester warms up. Diamonds (and, to a lesser extent, rubies and sapphires) are 'cold'. A crude test is to touch the stone against your lip to feel the 'coldness'. The Multi Tester measures this relative 'coldness', i.e. how quickly the heat from the tip is 'drawn' into the stone. Therefore it is most important that both the stone and the Multi Tester are at room temperature, otherwise any cold stone (including any large ruby or sapphire which is cool ) will register diamond. Conversely, a warm diamond will register not diamond. Diamonds become warm by being heated by the tip of the Multi Tester, so when testing the same stone you must wait two or three minutes between tests (especially with small stones) for the stone to cool down. Moissanite testing (electrical conductivity) The stone must be absolutely clean, preferably by cleaning with a cotton wool bud soaked in alcohol. A layer of grease can give a false reading, it is not good enough to wipe the stone with a clean cloth. The Moissanite test is not reliable for stones under 3 points, the current can spark onto the setting of the stone and gives false readings. You must place the test-tip in the exact centre of the stone, so be quite certain that you can see the probe and the stone clearly even if this means finding your reading spectacles or using a magnifier. If you do not have good close-up eyesight (or an eyeglass) and a steady hand you will have difficulty testing stones under 10 points. The reason for holding the tester so that you are touching the metal plates with one hand and the setting of the stone (or metal stone-holder) with the other, is that the electrical resistance is measured from the probe, all the way through your body and back to the stone. Therefore, if you are insulated (by wearing gloves) you will get a false reading. The Moissanite tester is for testing diamond-like stones, so please do not test household objects, as you may find that some register Moissanite and assume the Multi Tester is faulty. Page 7
OTHER USES FOR THE UV LIGHT The quality (wavelength) of the UV light in the Multi Tester is particularly good for UV testing. The UV light can be used for observing the fluorescence (glow) in UV security marks, which are otherwise invisible. These can be found in banknotes, cheques, cheque cards and anything marked with a UV security marker. UV light is also widely used to detect modern surface paint on antique porcelain or paintings, signatures added to drawings and paintings, and writing on letters and postcards that are too feint to see in natural light. On Uranium glass (Vaseline glass) it makes the entire object glow vividly. In all cases, it helps to use the light in dim (if not dark) conditions. Not all diamonds fluoresce to the same extent, not all diamonds fluoresce at all. Therefore, although UV light is not diagnostic, you can make use of the fact that diamonds fluoresce randomly. If you have several stones and they all react in exactly the same way, it is unlikely that they are diamonds. The fluorescence (and any phosphorescence a glow that remains after the UV light has been turned off) must be observed in darkness, e.g. a dark room or a special dark cabinet. UV light is also used to help colour-grade diamonds, but it is only of use to the professional diamond dealer or specialist jeweller who knows how to colour-grade diamonds in the first place. White diamonds that fluoresce under UV light also fluoresce under the UV that is present in daylight, and this can make a stone appear a better colour than it really is, and so the diamond-grader may wish to downgrade it by one or two colours. MAINTENANCE If the Multi Tester is not going to be used for an extended period of time (several weeks), remove the battery. Protect the testing probe (if bent or broken, your Multi Tester cannot be repaired), replace the cover when not in use. A flashing Wait light means LOW BATTERY. If you use an external (mains) power supply, it must be 9v DC 0.5A (center negative) otherwise the tester won t work, or you will burn it out, neither of which is covered by the guarantee. Page 8