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Technology of the Gemscale 50 and Gemscale 100

The research, design innovations and inventions engineered into the Gemscale 50 and the Gemscale 100 meet the needs of professional gem and diamond dealers in jewelry trade for a portable carat scale. Diamonds and gems are shown, sold and delivered by dealers who are on the road for up to six months a year.

An accurate, dependable and portable scale is vital to the trade. Gems must be weighed accurately for pricing and identification. Self-tests engineered into the Gemscale during the turn-on calibration prevent inaccurate readings and costly mistakes. A portable carat scale must be durable to perform after the rigors of traveling. The compact patented, ceramic sensor of the Gemscale makes this technology ideal for travel. The technology is also dependable as there are no fine hand adjustments to disturb in handling.

The capacitance technology developed by Gemscale engineer and designer John Borchard is a variable capacitor sensor in which the gap between two parallel ceramic plates is measured. The sensor coupled with a custom micro-processor corrects for off center loading and allows the Gemscale to be reduced to a weight of 1/2 lb., and a size small enough to fit into a jacket pocket. The capacitance technology used in the Gemscale improves the efficiency of operation. The microprocessor compensates for slanted orientations during turn-on calibration and this eliminates time consuming foot leveling necessary for accurate calibrations and readings for Strain Gauge scales.

The patented draught shield of sturdy polycarbonate is coated to the hardness of glass to resist scratches. It is then then sputtered with Indium Tin Oxide to prevent static charges from disrupting readings. This patented draught shield design acts as the scale's carrying case. As a case, the draught shield secures the calibration weight and weighing pan in the contoured body of the scale. This self-contained design precludes lost parts.

The Gemscale is powered by a 9 volt battery for 200 operating hours. An AC adapter is unnecessary with this technology. Nearly all analog circuitry was eliminated to reduce power consumption from 1200 milliWatts (mW) typical of Strain Gauge products, to 17 mW. There are no bad readings due to low battery voltage. The Gemscale is also equipped with automatic shut-off.

The Gemscale provides a 96% larger area weighing pan than competitors because, unlike Strain Gauge, placing a stone in the center of the pan is not critical for an accurate reading. Side placement has been adjusted for in the microprocessor's program.

Ease of operation is provided with a one button operation. One finger releases the draught shield. One button turns the scale on, calibrates, tares and turns the scale off. Simplicity of operation keeps weighing in a selling situation faster, more productive and more professional.

A new industry standard was set with introduction of the Gemscale 50 in 1991. They were sold the world over.

Technology of the Gemscale 55-125, Millicarat 50, and Dendritics 500

In 1993 we began a very long process to update this technology so as to improve the performance in vibration and increase the resolution.  Our initial goal was to create a portable Millicarat scale.  This was widely seen as impossible in the industry, and for good reason.  Haigis had made one for Sartorius, the "white scale", sometimes labeled "I. David".  This resolved only 10 carats down to 0.001 ct, and the rest of the range was a 100.00 ct x .01 ct scale.  Its power consumption was very high, as it was a force-motor design.

By 1998, we had our first Millicarat model.  We had to completely revise the electronics and upgrade to a much fancier computer chip, a so-called DSP (Digital Signal Processor) chip.  These were created primarily for the fast-moving telecommunications market.  Its power was not what we wanted, about 180 mW, which meant only 20 hours of operation.  Two years later, the chip became obsolete, and we had to scramble to redesign for a new chip.

In the year 2000 we had redesigned the digital electronics (and much of the analog, alas) for a second DSP generation.  Power was way down, largely due to the 3V components which were now available (as opposed to the original 5V parts).  We were back down to the good old 18 mW level of the original Gemscale 50.

But by 2001, that chip became obsolete too.  And rather than doing another complete redesign, we stopped there!

The Antistatic Technology of the Gemscales

Some information you can find as aspects of Draftshields and of Weighing Pans.

Other Technology Aspects of the Gemscales

Draftshields Draftshield Coatings Weighing Pans Capacitance Technology G50 Technology G50-G100 Advantages D500 Feature Plan Patents Gravity Zones Legal For Trade Sensors G50 Body Shapes Electronic Circuit BoardsG50 vs Tanita

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