Understanding how hazardous gases and particles disperse from leaks or explosions is essential to human safety. Aurora Scientific’s sensors have played a key role in large outdoor field studies of concentration fluctuations in dispersing plumes, building infiltration, evaporation and heavy gas dispersion. Our smaller gas sensors have been used in wind tunnels for plume tracking and evaporation experiments. Our gas sensors have helped researchers achieve their research goals in the field of environmental monitoring.
The Study Of Gas Dispersion and Other Environmental Monitoring
plume dispersion, concentration fluctuations, building infiltration/HVAC, heavy gas dispersion, evaporative dispersion, wind tunnel dispersion, outdoor dispersion
Outdoor Dispersion Products
Various disseminators are available for wind tunnel and outdoor experiments. These include simple manual disseminators to remote-controlled systems complete with flow measurement. Please contact us for further information.
Wind Tunnel Dispersion Products
Building Infiltration/HVAC Products
200B – Development of a Scalar Transport Probe
In 1997 Dr. Klewicki from the University of Utah and his team were working with hot-wire anemometers to measure turbulence in the atmosphere. They became aware of Aurora Scientific’s work with fast-response chemical sensors and approached us about developing a scalar transport probe. This was a device that could simultaneously measure turbulence and gas concentration. They required a gas sensor that was very small so as to not disturb the flow at the measurement location. It also needed to have high frequency response to allow correlation of the high frequency turbulence measurements with the concentration fluctuations. A final requirement was high spatial resolution in order to resolve the concentration fluctuations on a scale similar to that provided by the hot-wire anemometers.
Aurora Scientific’s R&D team had significant experience with fast response photoionization sensors but realized that a new instrument was required. Thus we started work on the 200B miniPID. To meet the requirement for small size the sensor head was separated from the more bulky control electronics. Work was done to miniaturize the sensor head and also to increase the frequency response of the sensor. A unique detector circuit board was designed, which improved frequency response with the added advantages of reducing noise and making the sensor less susceptible to noise from movement and vibration. Prof. Klewicki provided details of the physical layout of the hot-wire probes and requirements for mounting the sensor. This information was used to design the sensor case. Because of the importance of not disturbing the flow near the sampling point we used a fine needle as the inlet and rounded the case to minimize flow disturbances.
The new sensor was delivered to the Klewicki lab, where it was successfully used during outdoor field trials on the mud flats at Dugway Proving Ground in the fall of 1999. Data was also taken in a wind tunnel at the University of Utah. A paper was published (M M Metzger and J C Klewicki 2003 Meas. Sci. Technol. 14 1437. doi:10.1088/0957-0233/14/8/333) in Measurement Science and Technology describing the scalar transport probe and presenting results from the wind tunnel and outdoor experiments. Since that time miniPID sensors have been used in numerous wind tunnel and outdoor experiments looking at concentration fluctuations in dispersing plumes and in plume tracking studies.