Durability Of The Testing Acids - GOLDANALYTIX 06-03-00015 Benutzerhandbuch

silver, the abraison is not attacked or the color changes to
blue. After the test you can give a drop of acetic acid or
citric acid on the mixture, the smell disappears then. The
silver content affects the speed of the reaction. If your
test sample is pure silver the color change takes a little bit
longer than with sterling silver (925) or silver with lower
content. Anyway, sterling silver is colored blue on the
abraison because it contains copper.

9. Durability of the testing acids

The testing acids 8 and 14 carats as well as the silver
testing products 1 and 2 have almost no expiration dates
when stored closed (this only applies to silver testing
product 2 when still in its powder state). The testing acids
for 18 and 21 carats survive for about one year, the
platinum test acid for about 6 months. The silver testing
liquid can be used for about 1 month after being mixed
with water, after that, the silver test will be a lot slower.
Storing them in a cool place in general increases the
acids' durability. If you want to check their reliability after
a long time without using them, we recommend the use of
standardised test needles with established precioud metal
content.
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