An exemplary fill level measurement device comprising a radar module can be provided, along with method, computer-executable instructions and computer-readable medium. The radar module can comprise a receiving channel for receiving a radar signal reflected by a filling medium. The fill level measurement device can also comprise a test module for testing the functionality of the receiving channel. The test module can comprise a test input (for feeding in a test signal having a test frequency, and a feeding-in apparatus configured to feed at least part of the test signal into the receiving channel. The feeding-in apparatus can be configured to superpose and/or combine the test signal with the radar signal reflected by the filling medium. The receiving channel of the radar module can further comprise a mixing device having an intermediate frequency output. The mixing device can be configured to output the test frequency of the test signal at the intermediate frequency output when the receiving channel is functioning correctly.

A measuring device that measures the level of fluid in a tank, for example a level of an aqueous urea solution in a tank for catalytic converters of combustion engines. The measuring means include: at least one sensor including a capacitive element electrically coupled to an oscillator configured to deliver a signal S.sub.i whose frequency F.sub.iPAD is a function of the capacitance of the capacitive element; at least one sensor being intended to be disposed outside of the tank, so that the capacitance of the capacitive element varies based on the level n of the fluid, when the level is comprised between a first threshold h.sub.i-min and a second threshold h.sub.i-max; a processing module, coupled to at least one sensor, and configured to determine the level n of fluid in the tank based on the frequency of the signal S.sub.i.

A vibronic measuring device, e.g. limit level sensor, for determining and/or monitoring at least one process variable, includes a mechanically oscillatory unit, which is excited to vibrate by at least one drive unit based on an electrical signal S.sub.A. A receiving unit receives and converts mechanical vibrations into an electrical signal S.sub.E. A control and evaluation unit applies closed- and/or open-loop control of the vibrational excitation, and evaluates the signal S.sub.E with respect to the process variable. A vibration sensor pick up a sensor signal S.sub.S at the vibration sensor, and an analysis unit is supplied with signals S.sub.E and S.sub.S, and applies self-learning analysis of the input signals and transmits reliability information for the signal S.sub.E to the control and evaluation unit.

A method is based on measuring a distance to a reference reflector arranged at a known distance, in order to calibrate and/or monitor a coherent frequency modulation, continuous wave radar, fill-level measuring device, wherein the reference reflector can be reliably identified. To this end, a reference reflector executing oscillations toward the fill-level measuring device with an oscillation frequency is used, which is inserted in the beam path of periodically linearly frequency modulated transmission signals transmitted from the fill-level measuring device. The fill-level measuring device receives fractions of the transmission signals reflected back on reflectors in the container and records based on these received signals and their time correlation relative to the respectively associated transmission signal for each received signal an echo function, which shows the amplitudes of the received signal as a function of the associated position of the associated reflector. Based on the time change of a plurality of sequentially recorded echo functions and the oscillation frequency of the reference reflector, the position of the reference reflector in the echo functions is identified and its reference reflector position determined.

Fill level monitoring relates to a method for controlling the fill level of a collecting vessel, wherein the collecting vessel could be filled with a dielectric medium. A fill level is monitored by a monitoring circuit with a measuring capacitor, the capacity of which changes steadily in correlation with the fill level, at least beyond a fill level range of the collecting vessel. The method includes: determining a capacity of the measuring capacitor; determining the quality of the measuring capacitor; determining a permittivity of the dielectric medium on the basis of the quality of the measuring capacitor; determining a fill level of the collecting vessel on the basis of the determined capacity of the measuring capacitor and the permittivity of the dielectric medium; and fill level-dependent drainage of the dielectric medium from the collecting vessel.

A self-diagnosing FMCW radar level gauge and a method for providing self-diagnosing with a radar level gauge is provided in a radar level gauge comprising a transceiver, a mixer, a signal propagating device and a signal propagation path connecting the transceiver and the signal propagating device, a filter arrangement and processing circuitry. The filter arrangement provides a filtered intermediate frequency signal. The transceiver outputs either a diagnostic sweep configured such that a reference echo from the signal propagation path is detectable in said filtered intermediate frequency signal, or a measurement sweep configured such that the reference echo is suppressed in the filtered intermediate frequency signal and that a surface echo is detectable. The processing circuitry is configured to self-diagnose the radar level gauge based on the reference echo, and to determine the distance to the surface based on the surface echo.

A method of proof testing a rollover detection system in a field device system includes a fill level sensor for determining a fill level of a product in a tank, and a sensor arrangement to determine at least one of temperature and density at multiple locations in the tank, the method includes: providing simulated temperature and/or density values for the sensor arrangement, the simulated temperature and/or density values being indicative of stratification of a product in the tank; acquiring a fill level of the product in the tank, and the simulated temperature and/or density values for the sensor arrangement, and providing the fill level, simulated temperature and/or density values to a rollover evaluation unit; and receiving, from the rollover evaluation unit, an output indicative of a risk of rollover in the tank from the fill level and the simulated temperature and/or density values.

Disclosed are methods for checking the operational reliability of a radar-based fill level measurement device, which operates according to the pulse time-of-flight method. The methods include detecting controlled variables of the fill level measurement device, such as the signal amplification or the sampling rate. By comparing the controlled variable with a corresponding limit value, it can be determined whether the fill level measurement device is operationally reliable or whether the operational reliability of the fill level measurement device has been lost with increasing operating times because of the degradation of electrical components. It is also advantageous that, on the basis of the methods according to the invention, it is possible to make a prediction according to the principle of predictive maintenance regarding how much remaining operating time is estimated to be left until a possible functional failure of the fill level measurement device.

A level gauge includes an input circuit, a sensor part, and switching means, the sensor part includes electrode pairs arranged in a liquid level detection direction, the electrode pairs are divided into n groups, the i-th (i=1, 2, . . . , n) group is constituted with an electrode pair at the 2.sup.i-1(2k1)-th (k is a natural number from 1 to 2.sup.n-i) position from the lowermost position, one ends of the electrode pairs are connected to the input circuit, and the other ends belonging to the same group are connected to each other in parallel and connected to the switching means.

A computer-implemented method for operating a device for determining and/or monitoring a process variable of a medium, wherein the device comprises a sensor unit and electronics having at least one component with a binary input and/or output, wherein at least a first and a second value for an input and/or output signal of the component correspond to a first and/or second state of the component, comprises: detecting a first and/or second value for the input and/or output signal corresponding to the first and/or second state, comparing the first and/or second value with a first and/or second predefinable reference value for the first and/or second state, and on the basis of the comparison, detecting the presence of an electrically conductive substance in the region of the component.