Abstract: A non-intrinsically safely supplied measurement device (1) with a connecting device (3) having an “increased safety” type of protection for connecting the measurement device (1) to a feed connection (2) in order to supply the measurement device (1) with electricity, an electronic device (4) which contains electronic components of the measurement device (1), a display device (8), a sensor (7) made with “increased safety” or “intrinsic safety” type of protection, and an output circuit (9) that is without at least the “intrinsic safety” type of protection. The electronic device (4) has an “encapsulation” type of protection, the display device (8) has an “intrinsic safety” type of protection and the display device (8), the sensor (7) and the output circuit (9) are connected to the electronic device (4) via connections having an “increased safety” type of protection.

Abstract: A non-intrinsically safely supplied measurement device (1) with a connecting device (3) having an “increased safety” type of protection for connecting the measurement device (1) to a feed connection (2) in order to supply the measurement device (1) with electricity, an electronic device (4) which contains electronic components of the measurement device (1), a display device (8), a sensor (7) made with “increased safety” or “intrinsic safety” type of protection, and an output circuit (9) that is without at least the “intrinsic safety” type of protection. The electronic device (4) has an “encapsulation” type of protection, the display device (8) has an “intrinsic safety” type of protection and the display device (8), the sensor (7) and the output circuit (9) are connected to the electronic device (4) via connections having an “increased safety” type of protection.

Abstract: An optoelectronic keypad and a method for controlling an optoelectronic keypad for a measuring instrument, require a transparent touch screen, at least two touch-sensitive control buttons, at least two light emitters and at least two photodetectors, where said control buttons are located next to each other on one side of the surface of the touch-screen, the light emitters and the photodetectors are situated next to each other on the other side of the touch screen and each one control button, light emitter and photodetector are functionally associated with one another in a way as to constitute one action key, whereby pressing the control button of an action key causes the light emanating from the light emitter of that action key to be reflected at the actuated key and to impinge on the photodetector of that key.

Abstract: An optoelectronic keypad and a method for controlling an optoelectronic keypad for a measuring instrument, require a transparent touch screen, at least two touch-sensitive control buttons, at least two light emitters and at least two photodetectors, where said control buttons are located next to each other on one side of the surface of the touch-screen, the light emitters and the photodetectors are situated next to each other on the other side of the touch screen and each one control button, light emitter and photodetector are functionally associated with one another in a way as to constitute one action key, whereby pressing the control button of an action key causes the light emanating from the light emitter of that action key to be reflected at the actuated key and to impinge on the photodetector of that key.

Abstract: When measuring the velocity of fluid flow by measuring the voltage produced by magnetic induction applied to the fluid, measurement is affected by the electrochemical potential developed at the electrodes. This may be compensated by storing the total signal produced with a first value of the induction and subtracting this stored signal from the total signal produced at a second value of the induction so that the electrochemical potential cancels out.