Gem identification device and method based on thermal conductivity and surface resistivity

Abstract

The invention discloses a gem identification device and method based on thermal conductivity and surface resistivity. The device comprises a thermal conductivity sensor, a sensor temperature measurement and heating control module, a signal operational amplifier module, an AD acquisition module, a temperature and humidity sensor detection module, a high voltage generation module, an electric conductivity detection module, a single-chip microcomputer module, a memory module, a sensor probe contact metal alarm module, a low voltage detection module, a display module, a buzzer alarm module, a communication module, a voltage stabilization module, a power supply control module and a button module. The device and method are used for identifying and distinguishing diamonds, laboratory cultured diamonds, mullite, red sapphire, emerald, crystals, jadeite, spinel, tourmaline, topaz, tanzanite, garnet, cordierite, olivine, quartz, topaz and other gems, and are high in identification accuracy and wide in application range.

Description

technical field [0001] The invention relates to the technical field of gem detection, and more specifically relates to a gem identification device and method based on thermal conductivity and surface resistivity. Background technique [0002] As a special consumer product, gemstones have been symbols of achievement and wealth, power and status, love and eternity since ancient times. [0003] The rarity and high price of natural gemstones has led some to pass off high-value gemstones with similar-looking but inexpensive gemstones. With the continuous development of man-made technology, synthetic laboratory-grown diamonds have appeared on the market in recent years. These synthetic diamonds are very close to natural diamonds in terms of appearance, composition, hardness, thermal conductivity, and surface resistance, which has greatly troubled the gemstone trading market. Therefore, the identification of gemstones is very necessary. [0004] In the existing patents, diamonds...

AI Technical Summary

Problems solved by technology

[0010] At the same time, the unit time factor t is ignored. This result is reflected in the fact that it takes 200 milliseconds to measure a diamond (high thermal conductivity) to reach the value set by the circuit, and it takes 1500 milliseconds to measure a large colorless sapphire (low thermal conductivity). The millisecond time also reaches the value set by the circuit, resulting in a different unit time during detection, resulting in a difference of nearly 20 times in thermal conductivity between diamond and sapphire, such as image 3 As shown, but the test results confuse the two gemstones into the same result

[0011] 2. When testing the conductivity, the potential gradient factor is ignored, only the feedback voltage U0 after the high voltage passes through the gemstone is detected, and the voltage U before passing through the gemstone is not detected.

Due to the differences in the components of the booster circuit, the voltage value of the boosted high voltage fluctuates within ±10%, which causes the potential gradient U-U0 to be different during the test, resulting in poor consistency of the test results

[0012] At the same time, the influence of the ambient temperature and relative humidity on the test result is ignored.

Due to changes in ambient temperature and relative humidity during the test, the surface resistance of the tested gemstone changes, which in turn affects the test results

[0013] To sum up, the above shortcomings make the gem detectors on the market can only be used in a small range of room temperature and relative humidity environment, and can only detect gemstones with relatively large differences in thermal conductivity, and cannot distinguish between laboratory-grown diamonds and thermal conductivity. The rate is adjacent to the gemstone, the detection resolution is low, and the consistency is poor

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