Abstract
SUMMARY Equipment is described for the operation of thermal conductivity detectors with square-wave bridge current. The resulting ac output signal allows amplification without the need for low-level choppers. With phase-locked demodulation of the amplified signal, bridge unbalance signals of the order of 10 nV can be detected. This performance exceeds the requirements of presently available detector cells, which produce noise levels of the order of 100 nV. The instrument is compatible with most existing hot wire detectors and may be used with economical recorders. Air and other permanent gases can be reliably analyzed at levels of 0.02 μl, with detection limits of the order of 0.002 μl. This performance makes the instrument attractive in the field of air pollution and opens the way to further research in the design of low-noise detector cells.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
