Brief introduction to the characteristics of the h

Introduction to the characteristics of gas detection

characteristics of gas detection characteristics of gas detection tube the detection tube for measuring gas actually instrumentalizes the chemical analysis method. It is a quantitative, qualitative and fixed value detection method, which has the dual advantages of chemical analysis and instrumental analysis. (1) Easy to operate. When in use, there are only two steps: special sampling and test result display, which are almost carried out at the same time, providing great convenience for professional inspectors. As long as the operators follow the operation methods of the instruction manual to create product tests that meet the current and future performance requirements, they can be applied. (2) Fast analysis. Due to the convenient operation, the time required for each analysis is greatly shortened. Generally, the results can be obtained in only tens of seconds to a few minutes. Its analysis speed is incomparable to any chemical analysis and instrument method. (3) High measurement accuracy. The fluorine lined butterfly valve simulates the field analysis conditions on the determination of the content scale of the detection tube, and uses different standard gases for calibration, which overcomes the method error that is easy to be brought into the analysis due to the small influence of chemical paper separation and double gummed paper. At the same time, human error is reduced. (4) Good adaptability. There are three kinds of detection tubes: low concentration, conventional concentration and high concentration, ranging from zero to a few ppm to tens of percent. They have a wide range of applications and provide great convenience for analysis. (5) Safe to use. It can be operated manually without power and heat source, and can be used safely in places with flammable and explosive gases. (6) Low price and easy to carry. Although the product is disposable, it is cheaper than the total price measured by other chemical and instrumental methods, and it does not need maintenance and repair, which is even cheaper. The detection tube is small in size and light in weight, which is convenient for operators to use in various environments. (7) Highly recognizable. It can measure various harmful gases and realize selective identification to a certain extent. Working principle of gas detection tubes various gas detection tubes are filled with a certain amount of detection agent (i.e. indicator powder) for the final flight test at the Marshall Space Flight Center of NASA in Huntsville, Alabama, in a fixed glass tube with a finite length and inner diameter, fixed with stopper, and then sealed and processed at both ends of the glass tube. Detection agent is a substance that adsorbs some chemical reagents that can react chemically with the substance to be tested and change color on the surface of solid carrier particles. The choice of chemical reagent and its chemical concentration ratio on the carrier determine the material composition and measuring range of the detection tube. The heart of the detection tube is the indicator powder installed in the glass tube. The detection of harmful gases in the air is based on the release of colored reactants when the measured sample passing through the tube reacts with the indicator powder in the tube, Form "shading layer" "And. The indicator powder is generally composed of a carrier and a chemical reagent. The chemical reagent is coated on the surface of the carrier, so that as few reagents as possible form the largest possible contact area, so as to obtain the indicator powder with a great ability to pass through the surface. It should choose those reagents that can produce a clear color of the reaction product film and change the color of the original indicator powder when they quickly react with the gas to be tested. Inspection of the detection tube Measurement is a linear colorimetric method. In addition to strictly controlling the tube making technology (including the formulation and implementation of the new national standard for polyurethane waterproof coating, which has become a top priority), it also requires that the indicator powder react with the gas to be measured quickly, with high sensitivity, obvious color change, and that the reactant cannot be volatile, with good reproducibility, and the long-term storage (within the validity period) performance remains unchanged