You can purchase one of these kits through a jewelry tool supplier. The kit will contain all of the materials that you’ll need along with a set of detailed instructions. Make sure to read the instructions carefully before beginning and conduct an inventory of the supplies before starting. These kits can be quite affordable, if ordered online. They start at around $30. Your kit will contain a number of needles that you’ll use for testing different types of gold. Look for a karat value marking on the side of the needle. Each needle will also have a colored gold sample at the tip. Use the yellow needle for yellow gold and the white needle for white gold. Turn the piece around until you find a less noticeable spot. Hold an engraving tool firmly in your hand and make a small divot in the metal. The goal is to expose the deeper layers of the metal. Since you are working with acid, it’s important to don thick, but fitted, gloves. Eye protection is also a good idea, just to be extra cautious. Avoid touching your face or your eyes while working with the acid. Select the proper needle for the gold type. Then, hold the needle tip directly over the notch. Push the plunger of the needle down until a single drop of acid drops into the divot. Look closely at the divot that you made earlier and where you just applied the acid. The acid will react with the metal and may turn a particular color. Generally, if the acid turns a green color, this indicates that the piece is not pure metal, but instead gold plated or another metal entirely. Since testing kits have different color indications, make sure to read the color guide carefully as you interpret the test results.

How would you rephrase that briefly using Chinese?
为了估测出更加接近标准的纯度数，你可以购买一套酸液检测设备。 检查测试针上的K值标签。 用雕刻工具在首饰上凿出一个缺口。 带上防护手套和安全眼镜。 将一滴酸液滴在缺口上。 观察并判断结果。