The present invention provides a transmitter for predicting stress on a formwork element (10) during and/or after pouring a building material (M), in particular concrete, into a space enclosed by a formwork (2) including the formwork element (10), the formwork element (10) comprising a form face (12) and a support structure (14) which is attached to the form face (12) and supporting the form face (12), wherein the form face (12) is separated from or integrated into the support structure (14), the system (1) comprising data acquisition means (16a, 16b, 16c, 16d, 16e), at least one sensor unit (18a, 18b, 18c, 18d, 18e), a control unit (20a, 20b, 20c, 20d, 20e) and a transmission unit (22a, 22b, 22c, 22d, 22e).