Regarding the cleaning of pressure gauges

Do you clean the U-tube or the mercury? Do you still need to clean the mercury? Just switch it directly

Generally speaking, one has to clean the mercury first, right? I’ll only replace it if something that can’t be cleaned gets mixed in. With the economic crisis this year, I try to save wherever possible~:victory:

Hehe, try using concentrated nitric acid; if that doesn’t work, use \"aqua regia\"! ~

Concentrated nitric acid? Can that concentrated nitric acid be separated easily once it gets mixed in? What to do with the water in it? . . . There will also be some water in the bubbles, right?

Sulfur can be used. Sulfur reacts with mercury to form mercury sulfide, thereby removing the mercury! 1. Mercury is a chemical element, commonly known as quicksilver (mercury can also be written as Hg). Its chemical symbol is Hg, and its atomic number is 80. Its valence electron configuration is 5d10 6s2; it is a liquid transition metal with high density and a silver-white color. Due to this property, mercury is often used to make thermometers. 2. Characteristics: Mercury has poor thermal conductivity but good electrical conductivity. 　　The density of mercury is 13.6×10^3 kg/m^3. The freezing point of mercury is -38.87°C, and its boiling point is 356.7°C. Mercury can easily form alloys with almost all common metals, including gold and silver, but not with iron. These alloys are collectively referred to as amalgams (or mercury alloys). 　　Mercury has a constant coefficient of volume expansion; its metallic activity is lower than that of zinc and cadmium, and it cannot displace hydrogen from acid solutions. In common mercury compounds, its valence is +1 or +2. Very few +3-valent mercurides exist. 　　Commercial transactions involving mercury are generally measured in units of a \"flask\", which weighs about 34.5 kilograms.

I’m dizzy. . . . . . If mercury has been removed, what’s the use of this pressure gauge? . . . :L

I found some information and would like to share it with everyone~~:victory: I. Preparation of the cleaning solution: Solution A: Sodium sulfite is added to an equivalent concentration of sodium nitrite solution to achieve saturation (prepared just before use). Solution B: A 1:1 (V/V) mixture of nitric acid. II. Cleaning method: 1. Pour the mercury that needs to be cleaned into Solution A, soak it there and shake several times; after half an hour, pour out Solution A and wash the mercury several times with distilled water. 2. Pour the mercury that has been treated with Solution A into Solution B, soak it there and shake several times; after half an hour, pour out Solution B and wash the mercury several more times with distilled water before it can be used again. The results are quite satisfactory. However, there seems to be some issue with the volume concentrations of \"equivalent sodium nitrate\" and nitric acid; I was wondering if anyone familiar with this topic could provide an explanation. :) This post was last edited by scene000 on 2009-4-10 10:20 ]