Swath width

A field test was conducted by spraying a commercial oil spill-dispersant (Corexit 9527) from aircraft [696]. Test objectives were to determine the efficiency of delivering the dispersant to a selected target using a large aircraft and to compare various measurement systems for droplet size and spray pattern distribution. The results indicated that aerial flights up to 46 m can produce droplet sizes and swath widths that would be operationally effective for an oil spill. 

Figure 7 illustrates the relationship of the (A) flagged swath width (B) actual total downwind or extended swath and (C) the airborne or what we identify as the drift-loss portion. Allowance must be made (such as buffer zones) for the swath displacement which actually is desirable in smoothing out the frequently rough distribution patterns in an aircraft swath (Figure 8). The portion of Figure 7 with which we should always be concerned is the airborne drift-loss from drops of 100 microns dia. and smaller.

Spray System 0 Application rate, swath width, spray... 

Weapons expenditure data strategic and tactical offensive and defensive strategies Determine emission rate, flight altitude, flight path and swath width requirements... 

Cluster nozzles are used either without a boom or at the end of booms to extend the effective swath width. One type is simply a large flooding deflector nozzle which will spread spray droplets over a swath up to 70 feet wide from a single nozzle tip. Cluster nozzles are a combination of a center-discharge and two or more off-center-discharge fan nozzles. The spray droplets vary in size from very small to very large, so drifting is a problem. 

Products for use in all these types of equipment (except aerosols filled at low or high pressure) are prepared as concentrates. Because rate of knockdown in these circumstances is not as critical as in domestic situations, these may be diluted with oil or water as desired with little overall alteration in performance. There are many products available with a large variety of different mixtures of pyrelhroids and PBO. The general rates of application and levels required lo give good performance can be defined within limits these are indicated in Table 15.5 below. It is of the greatest importance that the spray cloud is distributed as uniformly as possible throughout the area to be treated. Indoors this is easily related to volume, but outdoors efficacy will depend upon how much the density of obstacles, the wind speed and the effective swathe width affect the ease of distribution of the spray cloud. 

The basic near range sensors are the infrared and ultraviolet detectors, often coming together as IR/UV-sensor, in most cases in a line-scanner (LS) assembly. The IR/UV-LS is a passive bi-spectral remote sensor that is sensitive in the thermal infrared (TIR) between 8 and 14 pm and in the near ultraviolet (NUV) between 0.32 and 0.38 pm. At an aircraft altitude of 300 m its swath width amounts to approximately 500 m. This sensor on the one hand is used to measure the thermal emission of the sea surface in the TIR and on the other hand serves for the detection of highly reflecting... 

Swath width is basically a function of the spray angle, provided that the user maintains the nozzle at a constant distance from the target area being treated. Some users have added a weighted chain or string to part of the lance as a guide... 

Because it is applied as a volatile liquid, anhydrous ammonia must be injected 15 to 30 cm below the surface of the soil this usually is accomplished by an application knife such as those shown in Figure 10.3. Often in sandy, loose soil ammonia is applied by an ammonia chisel, also shown in Figure 10.3. Anhydrous ammonia is usually metered by a variable orifice-type meter or by a piston pump, The rate of application using the orifice meter is determined by the speed of the applicator, the swath width, and the orifice opening. Piston pumps are usually actuated by a drive-chain operated by a sprocket attached to a wheel of the applicator. Application rate is changed by changing the length of stroke of the piston the rate is independent of the applicator s speed. 

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