Clamping force measuring instrument for radial clamping means having the following features: a. the clamping force measuring instrument has at least one force sensor (26; 46) for detecting a clamping force applied to at least one measurement surface (24; 44) of the clamping force measuring instrument by a clamping means in a radial direction outwards or in a radial direction inwards relative to a centre axis, and b. the clamping force measuring instrument has an evaluation device for evaluating sensor data of the at least one force sensor (26; 46), and c. the evaluation device comprises: • a radio interface for communicating data to a receiver and/or • a memory for storing data for the purpose of later read-out via a cable connection or a radio connection and/or • a display device for displaying data, and d. the clamping force measuring instrument is embodied as a modular clamping force measuring instrument and comprises at least two modules, namely an evaluation module and a sensor module (20; 40), and e. the sensor module (20; 40) comprises at least said one measurement surface (24; 44) and the force sensor (26; 46), and f. the evaluation module has the radio interface, the memory and/or the display device, and g. the clamping force measuring instrument has a coupling device, and h. the sensor module (20; 40) and the evaluation module are configured for mechanical coupling to one another by means of the coupling device and each have a data connection device (28, 48, 68), wherein the two data connection devices (28, 48, 68) can be connected to one another in order to produce a data connection in the event of the sensor module (20; 40) being mechanically coupled to the evaluation module, characterized by at least one of the following features: i. the evaluation module is configured to read out at least the unique identification of the sensor module (20; 40) via the data connection in addition to sensor data of the at least one force sensor (26; 46) and optionally further sensors of the sensor module (20; 40) and to store, to communicate or to display said identification together with the sensor data, and/or j. the evaluation module is configured to read out calibration data regarding one or a plurality of sensors (26; 46) of the sensor module (20; 40) via the data connection in addition to sensor data of the at least one force sensor (26; 46) and optionally further sensors of the sensor module and to use said calibration data for correcting the sensor data and/or to write calibration data to a memory (30; 50) of the sensor module (20; 40). a. the clamping force measuring instrument has at least one force sensor (26; 46) for detecting a clamping force applied to at least one measurement surface (24; 44) of the clamping force measuring instrument by a clamping means in a radial direction outwards or in a radial direction inwards relative to a centre axis, and b. the clamping force measuring instrument has an evaluation device for evaluating sensor data of the at least one force sensor (26; 46), and c. the evaluation device comprises: • a radio interface for communicating data to a receiver and/or • a memory for storing data for the purpose of later read-out via a cable connection or a radio connection and/or • a display device for displaying data, and • a radio interface for communicating data to a receiver and/or • a memory for storing data for the purpose of later read-out via a cable connection or a radio connection and/or • a display device for displaying data, and d. the clamping force measuring instrument is embodied as a modular clamping force measuring instrument and comprises at least two modules, namely an evaluation module and a sensor module (20; 40), and e. the sensor module (20; 40) comprises at least said one measurement surface (24; 44) and the force sensor (26; 46), and f. the evaluation module has the radio interface, the memory and/or the display device, and g. the clamping force measuring instrument has a coupling device, and h. the sensor module (20; 40) and the evaluation module are configured for mechanical coupling to one another by means of the coupling device and each have a data connection device (28, 48, 68), wherein the two data connection devices (28, 48, 68) can be connected to one another in order to produce a data connection in the event of the sensor module (20; 40) being mechanically coupled to the evaluation module, characterized by at least one of the following features: i. the evaluation module is configured to read out at least the unique identification of the sensor module (20; 40) via the data connection in addition to sensor data of the at least one force sensor (26; 46) and optionally further sensors of the sensor module (20; 40) and to store, to communicate or to display said identification together with the sensor data, and/or j. the evaluation module is configured to read out calibration data regarding one or a plurality of sensors (26; 46) of the sensor module (20; 40) via the data connection in addition to sensor data of the at least one force sensor (26; 46) and optionally further sensors of the sensor module and to use said calibration data for correcting the sensor data and/or to write calibration data to a memory (30; 50) of the sensor module (20; 40).