Near Intersection of I-35 & I-90 Southern Mn. | You don't say what you are applying. With a 4600, this could be liquid spray, NH3, Manure, granular or possibly Direct Chemical Injection. I will assume that you are applying liquid with a sprayer. If the product is NH3 then there is the possiblilty of vapor. My comments relate to liquid spray but are mostly applicable to the other products as well.
Again double check all your calibration numbers including the setup choices for US, SI, Turf, SP1, SP2, Liquid Boom widths, speed cal, meter cal etc.
If these are in fact correct then proceed with some other tests. When you say that the rate is off 20% and now 30%, is this based on the volume and area indicated by the 4600 or by known values such as field size and tank size?
If we know that the area reported is incorrect we can proceed in one direction. If we know that the total volume being recorded is incorrect we can proceed in another direction.
It would be helpful to compare the area of a known field to the value shown on the 4600. If these are in close agreement then the speed device (radar etc.), speed cal, boom widths and boom sense are operating properly.
If the these values do not agree and if the value shown for the 4600's total is less than the true area of the field the problem has been narrowed down. Some thoughts are: 1) Problem with the speed measuring device or the speed cal number being incorrect, 2) Problem with boom sense.
The 4600 does not have built in boom switches. The wiring from the individual boom switches splits and goes two directions. The electricity goes to the individual boom valve and also goes to the 4600 to inform it that a particular boom section is ON. If there is a problem with that portion of the wiring, the valve will open but the console is not aware of this and the computations will be based on an incorrect width (too small) and underapplication will result.
An easy way to test for boom sense is as follows: Disconnect the speed device (small connector to the main harness) and ENTER in a test speed of 10 MPH. Then observe the Area/Hour display. With all booms OFF, the value should be zero. Try each boom section one at a time. The value shown for the Area/Hour should correspond to the boom section width. That is larger sections should show larger values than smaller sections. If you find that one section opens its valve but the Area/Hour is shown as zero then you will know that the problem lies with that part of the wiring.
If there is good agreement between the known field size and the value reported on the 4600, you should check for agreement with the known volume (tank size) and the total shown by the 4600. If these are not in agreement (remember most tanks rarely hold what the markings indicate), then the problem is with the flowmeter, flowmeter cal or its associated wiring. If the total shown by the 4600 is too large then the system is thinking that it is delivering more product than it really is so it closes down the control valve somewhat more than it should. This results in under application.
This could be due to a faulty flowmeter or some problem with the wiring which causes the system to see "too many" pulses on the flowmeter circuit.
Edited by tedbear 7/6/2007 06:31
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raven 4600 rate controller
