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| Constant x Percentage x Hours = Degrees
This pivot make 360 degrees in 12 hrs.
.3 x 100% x 12 hrs = 360 degrees
Let say the pivot stops because of flat tire. I can measure the top ring on the pivot to get the degrees left to complete cycle. Lets say 55% left to being done. How long will that take at say 14% ( that is about 1 inch of water for me. )
C x P x H = D
.3 x 14 x__ = 55 degrees
Answer .3 x 14 = 4.2 55/4.2 = 13.1 hrs.
It is 3 p.m. When do I want to start the pivot ? Now ? No.
It will be done at 4 a.m.
Wait till 8 p.m. and it will be done at 9 a.m. the next morning.
or
I can start it now and just slow it down. How much slower. Just put the hours in to figure the percentage needed.
C x P x H = D
.3 x __ x 18 hrs ( that is from 3 .pm. to 9a.m. the next morning) = 55 degrees
answer .3 x 18 = 5.4 55 degrees/ 5.4 = 10.2 %
How do I know what the constant will be for any pivot ?
The easiest way I know of is to time the pivot for 360 degree circle at only one timer setting, like 14 %. It is best to do it on the second or later circle for the season. The pivot packs the ground and the time does change a little. We can get with in 15 min. of when our pivot will be done. We don't always need to know, but some times we do need to know. | |
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Speed of an Irrigation Pivot
