GEMSCALE 50 - GEMSCALE 100

(Written for Inco Vacuum Coatings in January 1996)

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 jewellery 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 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 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 in 1991. Gemscale 100 was introduced in May of 1993. They are now sold the world over.