1.Precious metal classification
Precious metal elements: osmium, iridium, ruthenium, rhodium, platinum,
palladium, gold, silver.
According to the GB11887-2002 , the jewelries made from precious metals sold in the market can be
classified in to 4 types: gold jewelry, silver jewelry, platinum jewelry and
palladium jewelry.
1> Gold jewelry
According to the gold content, gold jewelries can be classified into Karat
gold jewelry, 99.0% gold jewelry, 99.9% gold jewelry. 1K equals to 100% divided
by 24, that is 1K =4.1667%. The theoretical purity of 24K is 100%.
①The gold
content of 18K gold jewelry is above 750‰, which can be labeled as 18K or G18K,
G750, Au750, gold 18K and gold 750.
②The gold content of 99.0% gold jewelry
is not less than 990‰, which can be labeled as 99.0% gold or G990, Au990 and
gold 990.
③The gold content of 99.9% gold jewelry is not less than 999‰,
which can be labeled as 99.9% gold or G999, Au999 and gold 999. In the market
(especially in the overseas market) there are some gold jewelries of 9K (gold
content is not less than 375‰), 14K (gold content is not less than 585‰) and 22K
(gold content is not less than 916‰).
2> Silver jewelry
common silver jewelries in the market include:
①925 silver: silver content
shall not be less than 925‰, the other 75‰ may be copper or anti-oxidants, which
can be labeled as S925, or Ag 925 and silver 925.
②99.0% silver: silver
content shall not be less than 990‰, which can be labeled as S990 or Ag990 and
silver 990. 800 silver (silver content shall not be less than 800‰) can be seen
occasionally in the market.
3>Platinum jewelry
Common platinum jewelries in the market include: Pt900, Pt950 and Pt990.
①Pt900, Pt content shall not be less than 900‰, which can be labeled as
Pt900 or Platinum 900.
②Pt950, Pt content shall not be less than 950‰, which
can be labeled as Pt950 or Platinum 950.
③Pt900, Pt content shall not be less
than 990‰, which can be labeled as Pt990 or Platinum 990, 99.0% platinum. Pt850
(platinum content shall not be less than 850‰) and Pt750 (platinum content shall
not be less than 750‰) can be seen in the market occasionally.
4>Palladium jewelry
In the past palladium was regarded as blends into the platinum jewelry.
Palladium is a new member of precious metal jewelry family.
①Pd950, palladium
content shall not be less than 950‰, which can be labeled as Pd950 or palladium
950.
②Pd990, palladium content shall not be less than 990‰, which can be
labeled as Pd990 or palladium 990.
2．Application plans of X-ray fluorescence spectrometer for precious
metal testing
1>According to GB/T18043-2008 , X-ray fluorescence
spectrum can be used in testing surface content of precious metal jewelry and
entrusted inspection, and manufacturer internal management. Due to the special
circumstances of the jewelries and limitations of methods and principles, X-ray
fluorescence spectrometry can be affected by:
-
major difference in the elemental composition and content of tested samples
and reference materials
-
the tested samples have surface coatings or processed by chemicals
-
measuring time, shape of samples and measuring area of samples
2>how to improve the measuring accuracy
①Tested samples made into reference materials with the same mend
②Melt the
sample evenly and made into tablet for test; as for sample which can’t be
melted, polish the surface before test in case that the dirt on the surface
affects the testing.
③Operate normatively and prolong the measuring time.
Virtual spectrum shall perfectly match with the testing spectrum. As for uneven
samples, run the test several times and average the test results.
Instrument Introduction
EDX3000 is developed by Skyray Instrument based on our precious metal testing
technology and experience. It is integrated with unique product configurations,
testing software with complete functions, and user-friendly operating interface,
meeting the requirements for composition testing of precious metals. The human
design minimizes adverse effects, making the job of testing various elements
easier and satisfying most needs of the customer.
Features
long stable X-ray tube
Semi-conductor silicon electric refrigeration
system, instead of liquid nitrogen refrigeration.
Using Skyray Instrument
patented product-Signal Noise Enhance (SNE), greatly improving the measuring
stability and accuracy of spectrometer.
Built-in high resolution camera,
convenient for observing samples at any time.
digital pulse processor, fast
and accurate data processing
amplifying circuit
high-low voltage
power
single sample chamber, manual instrument cap switch, safe and
convenient operation
non-vacuum chamber
triple safety
models
multi-variant non-linear regression program
Independent matrix
effect correction model
Integral steel structure and elegant
appearance
Special software particularly developed, user-friendly operating
interface
non-standard samples can be tested accurately as
well
high-resolution graphics real-time display, care-free measuring
Technical index
instrument model: EDX3000
scope of measuring elements: from natrium (Na)
to uranium (U)
analytical accuracy: 0.05% (above 96%)
analytical scope:
1ppm-99.9%
measuring objects: powder, solids and liquids
working voltage:
AC 110V/220V (AC purified stabilivolt power)
analyzing 24 elements
simultaneously at one time
energy resolution: （155±5）eV
measuring time:
60-200 seconds
tube voltage: 5-50kV
tube current:
50μA-1000μA
temperature: 15℃-30℃
humidity: 35%-70%
weight: 30KG
Standard configuration
Si-Pin detector
high voltage 5kv-50kv
light pipe 50uA-1000uA
Signal
Noise Enhancer
MCA
single sample chamber
Application field
gold, silver, platinum, palladium, copper, zinc and nickel,
etc.
electronics and electrical appliances
toys and ceramics
metallurgy
and mining industries
