Lower-Link Draft Sensing
A method in which draft resistance is read through the two lower link pins. Because most of the load already passes through the lower links, the signal is more direct and more consistent across a wider range of implements; it also gives a meaningful measurement in cases where the top link is forced into tension.
In lower-link sensing the measuring point is where the force actually flows. In the classic application the lower link pins are connected to a torsion bar or a spring-loaded joint; on electronically equipped tractors force sensors placed inside the pins are used and the signal goes directly to the control unit.
- It also works with implements where the top link is not under compression.
- Because measurement is taken from two links, it can also pick up one-sided loading.
- In sensor-based applications, cable and connector maintenance is as important as mechanical adjustment.
Whichever method is used, draft sensing is the tractor's own equipment. Electronic retrofit kits fitted on the control side neither read nor change this measurement. If your tractor does not have draft control, fitting a kit does not add this feature; what the kit adds is the ability to give the raise-lower command from a joystick, a switch or a wireless remote control.
Context in which this term is used: Converting a tractor hydraulic lever to electronic control