Abstract: A method and a measuring device measure the density of fluid media with a sensor having a density measuring device. A frequency oscillator with mass balance is used as the density sensor and all components related to the frequency oscillator with mass balance for the oscillation behavior, oscillation excitation and oscillation evaluation, as well as the frequency oscillator with mass balance directly associated with the measuring and sensor electronics, are enclosed in a housing or cartridge. These components are used with the frequency oscillator with mass balance in the cartridge, and/or the frequency oscillator with mass balance together with the cartridge is adjusted or calibrated using measurement standards and adapted as necessary to the specific application. The cartridge with the frequency oscillator with mass balance is releasably or replaceably connected with the measuring device or its base body before the beginning of the measuring operation to investigate the media.

Abstract: A method and a measuring device measure the density of fluid media with a sensor having a density measuring device. A frequency oscillator with mass balance is used as the density sensor and all components related to the frequency oscillator with mass balance for the oscillation behavior, oscillation excitation and oscillation evaluation, as well as the frequency oscillator with mass balance directly associated with the measuring and sensor electronics, are enclosed in a housing or cartridge. These components are used with the frequency oscillator with mass balance in the cartridge, and/or the frequency oscillator with mass balance together with the cartridge is adjusted or calibrated using measurement standards and adapted as necessary to the specific application. The cartridge with the frequency oscillator with mass balance is releasably or replaceably connected with the measuring device or its base body before the beginning of the measuring operation to investigate the media.

Abstract: A micro hardness testing device (durometer) comprises a permanent magnet having a plunger. A spring arrangement has at least one strain gauge that provides a signal on bending of the spring arrangement. The spring arrangement is carried by the plunger. A penetration body is loadable via the spring arrangement, and the plunger is connected to a current supply. The strain gauge signal is converted to an electrical signal as a measuring signal for the force applied to the penetration body. The measuring signal is supplied to an evaluation unit. The plunger, the permanent magnet and the spring arrangement are enclosed by a housing adapted for insertion into a revolvable nose piece of a microscope. The housing approximates the shape and dimensions of an objective insert for the microscope. The penetration body is adjustable in an optical axis of the microscope.