A weigh platter assembly includes a weigh platter having a proximal edge and a lateral edge and an off-platter detection assembly. The off-platter detection assembly has an assembly field-of-view (field-of-view) extending from the proximal edge and constrained to have an assembly central field-of-view axis substantially parallel to the lateral edge and at least one lateral boundary substantially adjacent to the lateral edge. A light emission assembly has a light source and emits a light away from the proximal edge. A light detection assembly has a light sensor and detects at least a portion of the light reflected towards the proximal edge. A controller allows the measured weight to be recorded in response to a first value from the light detection assembly and prevents the measured weight from being recorded and/or provides an alert in response to a second value from the light detection assembly.