This shows a procedure called video-visualisation. An operator (wearing an air-fed visor) is shown spraying a vehicle. At the same time the concentration of isocyanates surrounding the sprayers visor is measured and recorded from second to second using specialist equipment from the Health and Safety Laboratory. These measurements are then superimposed on a graph showing isocyanate concentration on the Y axis and time across the X axis. There is also a small box above the graph that shows the numerical concentration from second to second.
The video plays in a screen above the graph and it is possible to show what activities cause the highest and lowest exposures. The Y axis scale is 0 to 5,000 micrograms/cubic metre. The graph of the spraying activity shows a series of peaks and troughs. Some of these peaks are extremely high (and, although not shown in this clip, were measured at nearly 20,000). When averaged over the spray job, the concentration in operator's breathing zone is 1708 microgram/cubic metre.