Irrigation in the Pacific Northwest

Percent Timer Setting

Older pivots only have a percent timer. Use to calculate a percent timer setting to apply a desired depth or finish in a desired time period.Use the full rotation calculator to find the approximate amount of time it will take for a pivot to make a full rotation. Calculate the time for a 1" application. To see the equations used in these calculators click here. Learn more about the units used on this page.


Percent Setting By Depth

Percent setting at known application depth (recommended to measure with catch cans):
%
Depth of water applied at the above setting:
Desired new depth to apply:
New percent timer setting to achieve desired depth:
%

 

Percent Setting by Desired Completion Time

Percent timer setting at known completion time
%
Known completion time
New desired completion time:
New percent timer setting for new completion time:
%

 

Percent Setting By 1" Application

Time for Full Rotation at 100%:
Application Depth Required:
Percent Timer Setting:
%

 

 

The Equations

These calculators use these formulas to determine the percent timer setting to achieve a specified application depth or completion time.

 

Percent Setting By Depth


Where:

= The new pivot percent timer setting to achieve desired depth (as a %)

= The pivot percent timer setting to achieve known application depth (as a %)

= Known application depth (in)

= Desired new application depth (in)

 

Percent Setting By Desired Completion Time


Where:

= The new pivot percent timer setting to achieve desired completion time (as a %)

= The pivot percent timer setting to at known completion time (as a %)

= Known completion time (hrs)

= Desired completion time (hrs)

 

Percent Setting By 1" Application


Where:

= The new pivot percent setting to achieve desired depth (as a %)

= Pivot full rotation time at 100% (hrs)

= Pivot full rotation time to apply 1 inch (hrs)

= Desired application depth (in)

 

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