Abstract: A position-determining device for a hand-held material testing apparatus detects a distance traveled by the material testing apparatus. The position-determining device includes at least one signal transmitter unit and at least one sensor unit. The signal transmitter unit is for an arrangement on a rolling element of the material testing apparatus. The signal transmitter unit includes at least one signal transmitter element configured to change a measurement signal as a function of a rotational position of the rolling element. The at least one sensor unit is provided for an arrangement on a chassis of the material testing apparatus and for detecting the measurement signal. The signal transmitter element is configured as an inductive signal transmitter element. The sensor unit is configured as an inductive sensor unit. The inductive signal transmitter element and the inductive sensor unit are configured for inductive coupling to one another.

Abstract: A method for locating an object hidden beneath a surface using a locating device is disclosed. At least one coupling signal dependent on the object is received by a receiving means of the locating device. Once the locating device has been placed on the surface, a first value Ci of the coupling signal is detected and the first value Ci is defined as value CBG for a background subtraction. In particular, whilst the locating device and the surface are moved relative to one another, at least one further value C of the coupling signal is detected and the value CBG for the background subtraction is re-calibrated by the at least one further value C if the at least one further value C is lower than the value CBG for the background subtraction. The re-calibration is suspended if a valid value CBG is identified for the background subtraction.

Abstract: A method for locating an object hidden beneath a surface using a locating device is disclosed. At least one coupling signal dependent on the object is received by a receiving means of the locating device. Once the locating device has been placed on the surface, a first value Ci of the coupling signal is detected and the first value Ci is defined as value CBG for a background subtraction. In particular, whilst the locating device and the surface are moved relative to one another, at least one further value C of the coupling signal is detected and the value CBG for the background subtraction is re-calibrated by the at least one further value C if the at least one further value C is lower than the value CBG for the background subtraction. The re-calibration is suspended if a valid value CBG is identified for the background subtraction.

Abstract: A charge pump includes: a control input for applying a control pulse, a pulsed current source for generating a current pulse in accordance with the control pulse, a direct current source for generating a direct current, and a current output that is connected to the pulsed current source and to the direct current source.