Abstract: An agricultural machine includes a chassis, a product tank containing a fluid, and a fluid distribution system in fluid communication with the product tank. The fluid distribution system includes at least one fluid outlet line configured to deliver a fluid to an agricultural field, at least one pulse width modulation valve in fluid communication with the at least one fluid outlet line, and at least one pressure sensor upstream of the at least one pulse width modulation valve, the at least one pressure sensor configured to measure a fluid pressure proximate the at least one pulse width modulation valve. The agricultural machine further includes a monitoring system configured to determine at least one of a duty cycle or a modulation frequency of the at least one pulse width modulation valve based on the fluid pressure. Related methods and monitoring systems are also disclosed.