+ Weighs when the telescopic boom is retracted or extended; to be decided at time of calibration, + normal accuracy about 1%, when truck is fitted with a bucket, worse with forks because the load center can vary, hence the weight arm and lifting force, + digital display in the cabin. Options: + printer on tickets or paper roll, + transfer of weight data to PC by chip card or GSM, 2 measuring principles are available:   A. Measure the hydraulic pressure:        a pressure transducer must be inserted between the check valve and the lift cylinder,        an inductive switch detects when the boom is at the proper height.   B. A strain gauge measures the bend of the boom:        independent of the hydraulic system condition and built-in valves,        permanent signal allows to mix and dose,        see the green picture.