Talk about the standard gas development of our country

1 Introduction
   Standard gas is Instrument evaluation criteria essential to the process of base amount of substance, it has reproduced, saved money transfer and other basic functions. Since the reform and opening up, the rapid development of China's high-tech industry, has greatly promoted the development of measurement standards matter, especially our major ethylene projects have been put into operation to drive the demand for a variety of standard gas surged. Since the standard gas manufacturing with less investment, effective fast industry characteristics, therefore, the current number of China's entry into the field has increased every year, making the standard gas market has experienced unprecedented competitive momentum, and this situation worse. The result of competition so that the majority of standard gas users to take the initiative, easily purchase price is very cheap products, but also caused a decline in profits in the industry, quality has been affected to varying degrees. In previous articles I have on a number of issues of standards that exist in the gas production process been discussed (see "Low Temperature and Specialty Gas" 2002 sixth 33). Based on today's market characteristics, again discussed on the problems of the standard gas, hoping to get readers to resonate, to promote China's special gas industry healthy, stable and orderly development.
 Two problems in our standard gas
 2.1 standard gas production qualification approval looser
     Preparation of standard gas comprises a plurality of links gas analysis and detection, gas cylinders processing, high purity raw gas production and purification (or purchase), preparation of standard gas and so on. Subtle errors occur in every aspect, gas quality standards will result in misalignment. Therefore, many well-known international gas company believes that a capital investment of industrial gases, specialty gases and gas competition is the standard technique. Difficult standard gas bottle price is usually more than one truck bottled industrial gases (in some places only sell 6 yuan of industrial oxygen bottle), and from imported standard gas price is very expensive. Since the standard gases traceable function, is the scope of national measurement control, in the quality of the dispute, it has the effect of arbitration. Therefore, the production tools needed to prepare a standard gas should have a very high sensitivity, but requires a series of well-trained professional and technical personnel. Therefore, the preparation of standard gas looks easy, but truly accurate, stable and reliable, but it is not easy. However, our current standard gas access threshold is too low, a research report alone will easily get a standard gas production licenses. You can see from the table of contents of the standard material, many varieties of standard material, and very difficult to prepare varieties. How true these so-called gold standard material is high, with foreign accuracy calibration gas there much difference, even for the same component from different manufacturers at the same concentration of the calibration gas can match the success of the majority of practitioners knew belly Ming.
 I recommend: In reviewing the standard material qualification, relevant departments have strict standards to control the few, human resources, infrastructure units have a strict application of the assessment measures, the terms of these assessment, examining ways to be open, fair, fair, effective, transparent, the only way to check from the source, so that our standard gas production has a higher starting point. At the same time, the relevant government departments to take responsibility, strengthen supervision of the standard gas production, but not out of the question then grab another tube.
 2.2 High-purity raw gas hard to find
     The quality of high-purity raw gas produced on the accuracy of the standard gas, plays a vital role. Uncertainty in the feed gas is extremely important parts of a standard gas combined uncertainty, therefore, there is no high-quality high-purity raw gas, it simply could not prepare the high accuracy of the standard gas. That is why, in China as early as the 1980s, in order to require the preparation of standard gas, the former Ministry of Chemical Industry for the development of high-purity gases given years of financial support, the majority of special gas workers has been carrying out gas synthesis, purification analyzes and other work, and achieved remarkable results. Therefore, we can find a variety of high-purity gases standard material early approval from the Standards Catalog.
 Because of high purity gases (such as: high-purity organic gases) the amount is small, hybrid varieties, high purity requirements and various purification devices to each other in order to avoid contamination, they can not share with each other the merger, therefore, in all market-centered environment, Jing Xiaxin really good job of each high-purity gases and easy. In recent years, due to increased competition in the industry standard gas, falling profits, the standard gas production plant for high purity gas purchase price of the raw material used is also very care about the poor quality of a large number of low-cost raw gas also will appear, such as the industry as a high-purity hydrogen sulfide hydrogen sulfide sold. In fact, the current market are mostly common to hydrogen sulfide sulfur hydrogenation (S + H2 a H2S) dry synthetic industrial grade H2S, which contains 3% to 5% H2, such a high impurity content, for the preparation of the component containing H2S the impact of calibration gas is obvious. On the market as a high-purity acetylene acetylene useful to industrial gas distribution, due to a large amount of solvent containing dissolved acetylene - acetone, so users often complain about the standard of acetylene gas are not allowed. In fact. Acetylene containing acetone how many depends on the ambient temperature, that is a big gap between winter and summer acetone containing acetylene, which is the same customers in the summer and winter concentration calibration gas bottles, but there is reason for great error. As a result, the user will always substandard products as qualified products, while the real encounter qualified but they think it is fake.
 2.3 Analysis of inadequate testing instruments
     Standard gas before and after the preparation, analysis and detection needs. In recent years, the standard gas component is being used by "10-6 to" relatively high lO-9 development, domestic equipment, instruments and other prices, but poor reliability; imported equipment quality is slightly better, but its price is more expensive, and updates faster. Time-scale gas production requires a variety of specialized testing equipment, foreign gas companies have a lot of advanced detection equipment, and therefore, the foreign gas valve procedure can often be seen using the injection method. In fact, they are in the preparation, in order to avoid dilution caused by multiple waste of manpower, material resources, the use of the method of preparation, and then analyzed by high-sensitivity instruments and equipment used is certified reference materials (CaM) were calibration. This method is often used in the N2-O2 calibration gas preparation. How to solve the domestic standard gas production plant due to lack of funds, lack of equipment problems will lead to a long-term difficult problem to solve. Currently the standard gas market competition, market difficult, Shexiang spend one million to buy imported equipment, is not an ordinary company can do. Inadequate or analytical instrument technology, however, is one of the important causes of many of the standard gas quality is not high.
 24 active ingredients need to be resolved cylinders processing technology
     In recent years, more and more high catalytic activity, people live and work in an environment more and more attention, this standard requires the active substances such as sulfur, chlorine, fluorine-containing hydrogen cyanide (HCN), ammonia- standard gas concentrations increasingly low. Due to extremely high chemical activity of these gases, in general cylinders, its stability is poor. Processing technology developed for cylinders attached great importance to various processing techniques have their own characteristics. Such as: nickel, gold, coated with organic polymer. In China, only "eight five" period to carry out work in this area too, but now, some processing technology still can not meet the needs of the market, such as the stability of the N2 ~ 10 × 10 a C12 concentration below standard gas need to be resolved. There are many standard gas preparation staff, inadequate attention cylinder handling, combined with a clear understanding of the user of this, so that the change of white steel valves do not change, do not do the coating. Such a standard gas for calibration alarm equipment, although under normal circumstances, do not see a problem, but this is undoubtedly useless alarm equipment. Some people think that as long as the so-called prediction and will avoid ingredients broken "eat" the problem, but if you do not analyze the match later, sometimes resulting in component content will soar. Therefore, early treatment is formulated to carry out cylinders reliable gas activity marked an important prerequisite.
 2.5 standard gas value
     After the standard gas prepared by the gravimetric method or other methods, we need a review or valuation analysis, especially for those in the preparation process may cause pollution, components easily sidewall adsorption at high pressure, the components may interact The calibration gas. After the preparation of stable, or re-evaluate its content value is in the process of preparation of standard gas indispensable process. Some of the gas through the instrument can be directly given value, such as: oxygen analyzers, water analyzers, these analyzes must be legal metrology instruments calibrated, but some components must be accurate and reliable reference material value. The usual practice is to choose on a calibrated standard material, as with a standard substance used to calibrate two standard material, or purchase in the industry have a certain influence and qualifications, the stronger units of the product to the given value. Due to the small number of primary standard material, variety, expensive, and therefore, in practice, in addition to the need for certified, the majority of standard gas counterparts rarely buy level standard. Because standard gas species complex, where there are certain instruments and experience gas production units and technical staff, basically using a custom approach to self-made standard calibration gas, some units with a gravimetric method for the preparation of calibration gas value from the distribution The standard gas, using this method there is no great value. Back in the 1980s, China's major laboratories basically static volumetric method for the preparation of standard gas, this method is used to calibrate some of the gas is still of great significance today. We have repeatedly CO, CH, OH, acrylonitrile, acetonitrile and other components of the standard gas formulated static volumetric method, good results. With the past is, in the big glass ball valve on the gas we use sophisticated component injection method with a combination of differential pressure gauge, while the balance of the gas, such as: N2H2, Ar, He, we are using the gravimetric method, because of the large volume of a sphere, mostly 5000 mL or more, so the use of high-precision scales, weighing error can be greatly reduced. Gravimetric method, the static volumetric method, a simple, safe, reliable, and accurate numerical advantage, is a very worthy of valuation methods.
 3 Conclusions
     Through the hard work of the majority of practitioners, Chinese standard gas made great strides, but compared with developed countries, there is still a gap, these issues require government departments and the majority of scientists and mutual cooperation and common solutions. Only in this way, China's standard gas industry can be healthy and orderly development.