Device (50; 50A; 50B) for a welding control, with a determining module for determining an expected value (L E, I E, M E) of a physical variable which occurs during a welding operation with a welding tool and is dependent on a force (F S (t); F S_ACT) which at least one electrode (22, 23) of the welding tool exerts on at least one component (5, 6) when producing a welded connection, wherein the welding tool is a resistance welding tool which is designed as a welding gun with two electrodes (22, 23), and a comparing module for comparing the expected value (L E, I E, M E) with an actual value (L ACT, In_ ACT, Mn_ ACT) of the physical variable which occurs during the welding operation with the welding tool in order to validate the plausibility of an actual value of the force (F S (t); F S_ACT) recorded during the welding operation with the welding tool, wherein the determining module is designed to determine the expected value (L E, I E, M E) with a model of the welding tool, wherein the model models the welding tool as a spring (211, 212, 213) and has at least one parameter (k_E, Tt) determining the spring (211, 212, 213), wherein the comparing module is designed to discontinue the welding operation and optionally output an error message as a message to the welding control if a difference between the expected value (L E, I E, M E) and the actual value (L ACT, In_ ACT, Mn_ ACT) of the physical variable is greater than a predetermined limit value, wherein the physical variable is the position of the at least one electrode (22, 23) of the welding tool and the model comprises a modelled upward arm bending (A B) of the welding tool, and/or wherein the physical variable is the drive current (In) of a drive device for driving the at least one electrode (22, 23) of the welding tool, and/or wherein the physical variable is a torque of the drive device for driving the at least one electrode (22, 23) of the welding tool. a comparing module for comparing the expected value (L E, I E, M E) with an actual value (L ACT, In_ ACT, Mn_ ACT) of the physical variable which occurs during the welding operation with the welding tool in order to validate the plausibility of an actual value of the force (F S (t); F S_ACT) recorded during the welding operation with the welding tool, wherein the determining module is designed to determine the expected value (L E, I E, M E) with a model of the welding tool, wherein the model models the welding tool as a spring (211, 212, 213) and has at least one parameter (k_E, Tt) determining the spring (211, 212, 213), wherein the comparing module is designed to discontinue the welding operation and optionally output an error message as a message to the welding control if a difference between the expected value (L E, I E, M E) and the actual value (L ACT, In_ ACT, Mn_ ACT) of the physical variable is greater than a predetermined limit value, wherein the physical variable is the position of the at least one electrode (22, 23) of the welding tool and the model comprises a modelled upward arm bending (A B) of the welding tool, and/or wherein the physical variable is the drive current (In) of a drive device for driving the at least one electrode (22, 23) of the welding tool, and/or wherein the physical variable is a torque of the drive device for driving the at least one electrode (22, 23) of the welding tool.