Coaxial lines tests

For coaxial lines, the process tube undergoes the whole series of tests prior to containment closure. 

Test methods that might be used for sulfur determination applications in fuels include techniques such as lead acetate paper tape, oxidative combustion followed by gas chromatographic separation for flame photometric detection [4], and energy dispersive X-ray fluorescence with coaxial proportional counter detectors [5]. The first of these two methods was recently issued as a new standard D 7041 by ASTM. However, these and other corrunercially available analyzers, such conventional on-line/at process sulfur by combustion and UVF analyzers typically require analytical cycle times of 4—10 min. This delay in reporting the sulfur concentration levels limits the real time detection capability of changes in the sulfur concentration of fast moving or rapidly changing transport or process streams. 

The probe and meter must be calibrated before being installed in the transfer line. The probe was installed, as shown by Fig. 4, in a vacuum-insulated liquid-hydrogen dewar. The temperature of the coaxial cable must be maintained at ambient conditions. If the temperature of several feet of the cable is permitted to vary from liquid—vapor temperatures during calibration to ambient temperature during a test run, errors will be introduced due to the capacitance variation of the coaxial cable with temperature. 

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