Gas Cell Essay Example | Topics and Well Written Essays - 750 words

Gas Cell - Essay Example Configured for gas sampling, the cell incorporates 2 valves, an inlet and an outlet, that enable flowing gas samples through the cell. In its solid and liquid vaporization configuration, the cell has an outlet needle valve from which a vacuum can be pulled and two (2) sample inlets. One inlet is a needle septa injection port on the top of the cell which is similar to the type used in gas chromatography. There is a second inlet in the form of a side port for inserting solid samples, which also doubles as the thermocouple port. Using the side port eliminates the need to recheck vacuum seals whenever the cell is opened to insert solid samples. The 250w heating jacket extends over the end of the cell so that both the cell body and the optics are heated, and allows operation at temperatures up to 1000K. Condensation on the optics is minimized by heating them to the same temperature as the sample chamber. A type J iron constantan thermocouple is provided with plugs which are compatible with the optional temperature controller. The cell body is type 304 stainless steel and an assortment of seals is provided - silicon rubber, viton and PTFE. Stainless Steel 304: SS 304 is the most versatile and the most ... It also has excellent low temperature properties and responds well to hardening by cold working. SS 304 is used in all industrial, commercial and domestic fields because of its good corrosion and heat resisting properties. Using SS304 is reducing the chances of failure of cell due to heating & creep. Creep Data Stress for a creep rate of 1% in 10 000 h. Temperature, oC 550 600 650 700 800 Temperature, K 823 873 923 973 1073 Stress, MPa 120 80 50 30 10 Environment Data/ Corrosion Rate The performance of SX 304 compared with other metals in various environments is shown in the following table. The corrosion rates are based on a 10 year exposure. Environment Corrosion Rate (m/year) SS 304 Mild Steel Rural 0.0025 5.8 Marine 0.0076 34.0 Marine Industrial 0.0076 46.2 So as compared to other metals stainless steel 304 is having very less corrosion rate, so this metal is best for the Gas cell. Stainless steel is also a preferred substrate because of its lower cost to fabricate into a mirror it requires multi-layer coatings, including gold as the primary reflective surface, which is expensive. Copper: Copper is a chemical element. Copper is malleable, ductile, excellent electrical conductor, non magnetic, resistant to corrosion, excellent heat transfer capacity, durable, & recyclable element. It is a ductile metal with excellent electrical conductivity and is rather soft in its pure state and has a pinkish luster which is. It finds extensive use as an electrical conductor, heat conductor, as a building material, and as a component of various alloys. Though copper has ductility property hence it can be drawn into thin wire. The ductility property of copper can reduce the chance of failure of cell due to