Flow monitors watch for plugged outlets
Flow monitors are like an extra set of eyes. You can’t watch every herbicide nozzle on a sprayer or every fertilizer outlet on a corn planter or sidedressing machine. But with a glance at a bank of clear plastic columns, you can instantly tell whether all outlets, including the hidden ones, are applying approximately the same rate. (Some farmers use a cab camera so they can check the monitors without turning around.) Flow monitors are inexpensive, simple, and reliable. And they work. Year after year, they prevent weed strips in beans and nitrogen skips in corn.
They don’t regulate the flow of liquid, and they don’t tell you how many gallons per acre of liquid are being applied. They simply tell you whether all outlets are applying roughly the same amount, which means within about 10% of each other. There are styles for both squeeze pumps and pressure pumps.
When all of the balls in all of the columns are lined up, the flow of liquid to the various outlets is uniform. When one ball is lower than the others (as shown in the photo), it means the flow through that column, hose, and outlet is too low due to a restriction or blockage. When one ball is higher than the others, it means the flow is too high. That’s typically due to a leak in a hose or fitting.
Three Companies Make Flow Monitors
Three companies make flow monitors: Willmar Fabrication, CDS-John Blue, and Wilger. Their products are fairly similar. They even have some interchangeable parts. But the ways in which two of these companies entered the market couldn’t be more different. In 1984, Minnesota farmer Steve Claussen designed the first flow monitor. His initial office was a basement room in downtown Benson, Minnesota, furnished with a card table and a phone. Today, his company, Willmar Fabrication, builds a wide range of equipment including sprayers, seed tenders, and, of course, Redball Spray Monitors (aptly named for the red balls that warn if a system is malfunctioning).
In contrast, CDS-John Blue, a 125-year-old pump manufacturer from Alabama, introduced the CDS-John Blue VisaGage II in the fall of 2009.
The third company, Wilger Industries, Ltd., was founded in Saskatoon, Canada, in 1976 by Wilf Wilger to build field sprayers. This company started making Wilger Flow View flow monitors about a dozen years ago. The U.S. arm of the company is located in Lexington, Tennessee. Wilger, Inc., is headed by Mark Bartel and has distributors throughout the U.S.
The original Redball flow monitor was sold in banks of four. According to Bartel, Wilger had a customer who was making hooded sprayers that only had three spray tips under each hood. Consequently, Wilger developed a modular concept to accommodate any number of outlets and, thus, entered the market.