We know that a weighing system must be rigid to get good results. We should also know that a three point system is inherently more stable than a four point system as three points define a plane. We know that we can convert a four wheel portable vessel to a three point system by using a double frame design “sandwich concept.
Now, let’s review the basics common to most types of load cells.
During a measurement, weight acts on the load cell's body and causes elastic deformation. The body has some spring constant. This strain (positive or negative) is converted into an electrical signal by a strain gauge installed on load cell.