Pulse width modulation sprayers: what we have learnt, correct operation and looking ahead
Published: 1 Apr 2019
What is pulse width modulation?
Pulse width modulation (PWM) is a spraying system where the flow rate is controlled by a pulsing solenoid at each nozzle, unlike a standard spray system that directly controls the overall flow rate. Learn more on page 1 of this factsheet.
- Pulse width modulation (PWM) sprayers are continuing to improve with new technology providing more consistent performance, individual section control and turn compensation
- Constant pressure maintains droplet size and spray quality over a range of speeds
- Low duty cycle operation can result in poor coverage especially with 10Hz systems
- Newer systems have high cycle frequency (15/30/100Hz) and combine other standalone spraying systems
- There are many misconceptions about the effective working speed range, correct nozzle size and determining the correct pre-set pressure
- When set-up and operated correctly PWM sprayers perform accurately
Frequently asked questions
Topics covered in this factsheet
- Duty cycle frequency
- Duty cycle percentage
- checking coverage and skips with water-sensitive paper
- PWM nozzle size selection process
- Types of PWM nozzles
- PWM nozzles available for 2,4-D application
- Can air-induction nozzles be used?
- Larger droplets with PWM
- Travel distance, pulse frequency and duty cycle interaction
- PWM hardware and application accuracy
Was this page helpful?