Inhibiting spray dispersion: method and apparatus

A method of regulating the state of wind sensitive means having first and second operating states comprising the steps of:

• establishing a wind speed threshold;
• establishing a first excursion limit and a second different excursion limit for a control means, said first and second excusion limits corresponding to said second and first operating states, respectively;
• establishing a first time constant defining a first time period for inhibiting transition from said first operating state to said second operating state at said first excursion limit;
• establishing a second time constant defining a second minimum time delay for transition from said second operating state to said first operating state at said second excusion limit;
• continuously sensing wind speed relative to said preselected wind speed threshold, and, during periods when wind speed exceeds said preselected wind speed threshold, advancing said control means at a rate according to said first time constant from said second excursion limit to said first excusion limit, and, during periods when wind speed is less than said preselected wind speed threshold, advancing said control means at a rate according to said second time constant from said first excursion limit to said second excursion limit without reference to operating state;
• and
• causing a change of operating state only upon said control means attaining an excursion limit different from the corresponding operating state, such that duration of operation in each of said operating states is at least said corresponding minimum time period and is maximized in inverse proportion to the time percentage of wind speed excursion across said preselected wind speed level relative to the current operating state.

A system for regulating the state of wind sensitive means under gusty wind conditions, said means having a first operating state and a second operating state, comprising:

• means for continuously sensing wind speed at a preselected location relative to a preselected wind speed threshold level;
• first means for switching the state of said wind sensitive means during said first operating state only after at least a first minimum period during which wind speed continuously exceeds said threshold level and for further inhibiting such state switching for a further variable length period proportional to the percentage of time during which wind speed does not exceed said threshold level, and
• second means for switching the state of said wind sensitive means only after at least a second minimum period during which wind speed continuously falls short of said threshold level and for further inhibiting such state switching for a further variable length period proportional to the percentage of time during which wind speed exceeds said threshold level,
• such that the duration of operation in each of said operating states is maximized in inverse proportion to the time percentage of wind speed excursion across said preselected wind speed level relative to the current operating state.