TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The method further involves using a semi-conductor device to selectively raise and/or lower the temperature within the housing at 60-130 degrees F to create the optimal temperature for the chosen impurity source, providing a supply of purge gas, introducing purge gas into the at least one conduit, where purge gas flows through the conduit during standby and causes the impurity source to diffuse into the purge gas that flows past the communication and changing the purge gas to pure gas when a calibration gas is desired, where the purge gas and the pure gas are introduced into the same conduit at different times, analyzing the calibration gas in an instrument and calibrating an instrument based upon the analysis and the known value of the impurity source, providing a sample gas comprising an unknown amount and/or type of impurities for analysis, analyzing the sample gas in the calibrated instrument (T1), comparing the results of the sample analysis with known results to determine the type and amount of impurities in the sample, making at least a portion of the at least one conduit from tubing that has a sulfur inert interior, supplying at least one additional conduit for a sample gas, where additional conduit leads to the instrument, providing a first conduit, a second conduit, and a valve connecting the first and second conduits to the at least one conduit, where the at least one conduit is the main gas conduit, providing a supply of purge gas, connecting the supply of pure gas to the first conduit, connecting the supply of purge gas to the second conduit, running purge gas through the second conduit during standby and opening the valve so that purge gas is introduced into the main conduit and flows past the communication and changing the valve to stop the flow of purge gas into the main conduit, allowing pure gas to flow through the first conduit into the main conduit when calibration is desired, using a flow controller to control the flow of gas inside the at least one conduit between 0-2 liters per minute, providing a vent, where gas of an undesired pressure is vented before it reaches the instrument, and using a rotometer to ensure a steady gas flow to the instrument.Preferred Apparatus: In (I), the temperature within the housing interior is maintained at 60-100 (preferably 75-77) degrees F during standby or when calibration is desired, by cooling or heating the interior as needed. The device for selectively raising and/or lowering the temperature is a semi-conductor heating or cooling device. (I) further comprises a purge gas source where the purge gas flows through the main conduit and passes by the communication when the apparatus is on standby.During standby the impurity from the source diffuses into the purge gas that flows past the communication; a valve that connects the supply of pure gas and the supply of purge gas to the main conduit, and where the purge gas and the pure gas are introduced into the main conduit at different times; a first gas conduit, a second gas conduit, and a valve connecting the first and second conduits to the main conduit, where the pure gas is introduced into the first conduit when calibration is desired and where purge gas is introduced into the second conduit when calibration gas is not needed. The valve determines which gas will flow into the main conduit; at least one conduit that leads to an instrument, and where the calibration gas is fed to the instrument that analyzes the gas; a device that is connected to the apparatus to an instrument that analyzes the calibration gas.The instrument is calibrated based upon results of the analysis and the known concentration of the source at a certain temperature range and flow rate; a fan or blower within the housing, where the temperature controlled air is circulated within the housing. The impurity source supplies at least one impurity. The source generates an impurity having a concentration of 10 - at least 50 nanograms/minute; a third conduit, where at least a portion of the third conduit is located within the housing and where a sample gas is introduced into the third conduit. The sample gas is conveyed through the third conduit to a calibrated instrument for analysis. The main gas conduit and the first and third gas conduits are made of sulfur inert tubing.The apparatus holds several devices that each produces a different impurity; a flow controller, where the flow controller allows a flow of gas at 0-2 liters/minute; a pressure indicator and a back pressure regulator that monitors the pressure of gas in the main conduit and regulates the flow path of the gas; a device to vent gas from the main conduit if the pressure of the calibration gas drops below 35-40 psi; an indicator that alerts an operator if the pressure of the gas in the conduit reaches an undesired pressure; a solenoid valve that controls the flow of gas leading to at least one instrument.(II) additionally comprises the first and the second gas conduit, where the first conduit is connected to a source of pure gas and the second conduit is connected to a source of purge gas. The first and second conduits are connected to a main conduit by a valve that determines which gas will flow into the main conduit; fittings, where the internals of the fittings are coated with sulfur inert coating to prevent permeation of sulfur into the fittings. The impurity source is placed in a header or manifold that is located within the housing and that communicates with the conduit; several headers, where each header holds a different source. The switch for the semi-conductor device is manually controlled and/or automatically controlled. The impurity source of (II) produces at least one impurity of a known concentration of 10 - at least 50 nanograms per minute that is measurable in ppm or ppb. (II) is contained within a portable case. A 12 volt direct current power supply is used to operate (II). The housing of (I) and (II) is made of aluminum. The impurity source of (II) and the system produces at least one impurity of a known concentration of 10-50 nanograms per minute that is measurable in ppm, ppb, or ppt. (T1) comprises a sulfur analyzer and/or a gas chromatograph.Preferred System: The system further comprises the purge gas supply, the valve, the first gas conduit, the second gas conduit, the sample gas and a rotometer between the main conduit and the gas chromatograph. Either pure gas or purge gas is introduced into the main conduit to flow past the communication. The valve is changed to stop the flow of purge gas into the main conduit and pure gas is allowed to flow through the first conduit into the main conduit when calibration is desired. The main conduit is made of sulfur inert tubing. The system is used in conjunction with an instrument to be calibrated, where the instrument analyzes the calibration gas. The instrument is calibrated based upon the analysis and the known value of the calibration gas. The instrument comprises a gas chromatograph, a sulfur analyzer, a gas monitoring system or a hydrocarbon analyzer.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The impurity source is selected from acetaldehyde, acetic acid, acetone, acetonitrile, acrylonitrile, benzene, 1,3-butadiene, n-butane, tert-butyl mercaptan, sec-butyl mercaptan, butyl mercaptan, carbon dioxide, carbon disulfide, carbon monoxide, carbonyl sulfide, chloroform, di-isopropyl methyl phosphonate, di-methyl methyl phosphonate, diethyl sulfide, dimethylether, dimethyl disulfide, dimethyl sulfide, ethanol, ethyl mercaptan, ethylene oxide, formaldehyde (para), freon-11, freon-21, methane, methanol, methyl chloride, methyl mercaptan, methylene chloride, propane, propyl mercaptan, propylene oxide, styrene, thiophene, toluene, vinyl acetate, vinyl chloride, water, meta-xylene, ortho-xylene and/or para-xylene.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The purge gas and the sample gas are carbon dioxide, nitrogen, oxygen, helium, argon, carbon monoxide and/or hydrogen. The impurity source is selected from ammonia, arsine, boron trichloride, boron triflouride, chlorine, hydrogen chloride, hydrogen fluoride, hydrogen sulfide, iodine, hydrazine, nitric oxide, nitrogen dioxide, nitrogen trifluoride, nitrous oxide, oxygen, phosgene, phosphine, silane, silicon tetrachloride, silicon tetrafluoride and sulfur dioxide.