Curtis Dyna-Fog MAXI-PRO 2D ULV, Instruction Manual For Operation And Maintenance

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19
MEASURING LIQUID FLOWABILITY (VISCOSITY)
In order to achieve consistent results in generating aerosols with a volume-median-
diameter (VMD) in the sub 20 micron range, several variables must be kept under
control at the same time. The ability of an aerosol generator to consistently break up a
liquid into appropriate sized droplets depends on (3) key elements:
1 . The available energy flow (air flow) through the nozzle is governed by the blower
speed. As the air mass and its velocity through the noz z le decreases, the droplet
size (VMD) will increase assuming that the liquids viscosity and flow rate remains
constant.
2. The flow rate of the liquid governed by the speed of the liquid pump.
3. The viscosity of the liquid.
Various liquids have different viscosities. Viscosity is defined as a fluids resistance to
flow commonly measured in units of a centipoises (CP). Generally, the thicker the liquid,
the greater the viscosity and the higher the CP number. Examples of some liquid
viscosities are:
LIQUID VISCOSITY (CP)
WATER 1
DIBROM 3-4
PYRETHRIN, RESMETHRIN 6-7
DURSBAN 1.5 ULV 12-14
TECHNICAL MALATHION 28
By measuring the flow ability of a liquid, adjusting the engine speed to produce the
desired nozzle boom pressure, and by setting the flow rate on the digital readout remote
control box, accurate particle size can be achieved.