When this yellow light is lit, it tells the milkers that one of the bulk tanks is nearly
full and it’s time to be thinking about switching over to the other tank. (An audible alarm also will sound when the tank is full.) This allows the milkers to monitor the situation from the parlor without having to walk over to the bulk tanks and check progress. A red light on the panel lights up if someone forgets to turn on a bulk-tank cooler, notes Lee Holtmeier, manager of Linn Willow Creek Dairy in Linn, Kan.