Spraycare trailed sprayer.

[harperfarmer]

Evening all. Having a few issues with a recently purchased spraycare machine. It's a 3200l trailed and sprays nicely however it isn't applying the correct rate. I'm saving the desired application rates in the teejet control box but doesn't seem to be making any difference?! The settings are correct in terms of nozzles used and pressure is up. It's currently spraying 185l/ha water rate despite the box reading that it should 320l/ha (had to adjust it that much to get it up to 185l.....ideally want to put on 200l) Has anyone else has similar issues!? Is this likely to be a box issue or a mechanical issue on the sprayer?! Thanks

 

[Al R]

Not familiar with the make but I’ve done enough spraying on a variety of lakes. More than likely speed sensor is wrong! If it’s out by 130% then the product specific gravity could be on liquid N (1.30kg/litre) instead of on water (1.00kg/litre)
I’d look at wheel speed sensors on the sprayer or is it on radar?

 

[essex man]

You are spraying on auto or manual?

 

[Lukehaynes]

This shouts to me that the speed sensor is out of calibration.

 

[TripleSix]

Is the width setting in the box correct?

Speed reading ok?

What pressure are you making? Anything under 1 bar will not be fully opening the drip stops and will give a false reading and under apply.

 

[harperfarmer]

Thanks for the replies everyone! I'm spraying on auto currently. Interestingly not that id given it any thought but we've just changed the wheels from rowcrops to some purchased wider flotations!? Will this have affected things?! Pressure is set at 2.0 bar and adjusts itself accordingly as speed increases the pressure builds to keep the same rate of application.

 

[Lukehaynes]

Thanks for the replies everyone! I'm spraying on auto currently. Interestingly not that id given it any thought but we've just changed the wheels from rowcrops to some purchased wider flotations!? Will this have affected things?! Pressure is set at 2.0 bar and adjusts itself accordingly as speed increases the pressure builds to keep the same rate of application.

It will definitely affect it. Most sprayers of that age have a set of magnets on a disc on the axle, these pass an electro magnet which sends a pulse to the controller.

Usually you would be required to travel 100m with the computer counting the pulses I’ve that distance and therefore giving a speed reading. The difference in circumference of wheels will affect the number of pulses over 100m giving a different speed signal.

 

[harperfarmer]

It will definitely affect it. Most sprayers of that age have a set of magnets on a disc on the axle, these pass an electro magnet which sends a pulse to the controller.

Usually you would be required to travel 100m with the computer counting the pulses I’ve that distance and therefore giving a speed reading. The difference in circumference of wheels will affect the number of pulses over 100m giving a different speed signal.

This sounds like it could definitely be the case!! Thanks very much explains a lot!

 

[Brisel]

Recalibrate the speed sensor for the new wheels. A quick spin up the road with the box on should tell you what it thinks the speed is vs what your tractor/GPS says.

 

[essex man]

Is the rate steady or is it working hard, I had an intermittent leak on suction side once and controller couldn't cope with pressure fluctuation in auto which resulted in rate being too low

 

[essex man]

Try spraying 185 on manual.
Will eliminate a few things if it can't

 

[harperfarmer]

Is the rate steady or is it working hard, I had an intermittent leak on suction side once and controller couldn't cope with pressure fluctuation in auto which resulted in rate being too low

Pretty steady tbh. Certainly doesn't seem to go up and down too much.

 

[fudge]

Is the control box a teejet 844? Is the sprayer equipped with a flo meter? it is possible to programme the 844 box to be either pressure or flo based depending on whether the sprayer has a flo meter or not.

 

[Lukehaynes]

Another thought I had, is the pressure gauge reading correctly, can you check it with another perhaps?