Researchers achieve real-time detection of low gas concentrations
>formatting linkAllowing gas detection and identification in just seconds,
> approach using a coherent control strategy offers promise for
> real-time monitoring in environmental, health and industrial applications > Source:
> Optica
> Summary:
> Researchers have developed a method for quickly detecting and identifying
> very low concentrations of gases, which, could form the basis for highly
> sensitive real-time sensors for applications such as environmental monitoring,
> breath analysis and chemical process control.
>
> Interesting method to stop a quartz tuning fork
It's a fairly old-fashioned technique - infra-red spectroscopy has been around for a whole,and if you want to detect low gas concentrations you could always use long-path-length absorbtion cells.
Ring-down detectors are an interesting variant on that approach.
The tuning fork detector may be a novel innovation, but it's less obvious that is a useful one.
"Stopping" a high-Q resonator fast is easy enough, but then you have to wait until the resonant movement builds up again - unless you have one of John Larkin's fast-start resonant devices.