摘要:
The present invention pertains to a pipetting apparatus and method capable of detecting a liquid (9, 9') within an intermediate section (4) of a pipette tube (1) of the pipetting apparatus. The intermediate section (4) is located between an upper section (2) of the pipette tube (1) at which a first electrode (10) is arranged and a lower section (3) at which a second electrode (11) is arranged. The first and second electrodes (10, 11) form a measurement capacitor and are operationally connected to an impedance measurement unit (13), which is adapted to detect whether liquid (9, 9'), such as a portion of a sample liquid (9) or system liquid (9'), is present within the intermediate section (4) based on the measured impedance or change of impedance, e.g. an increase of the capacitance and/or a decrease of the resistance, of the measurement capacitor caused by a presence of the liquid (9, 9') within the intermediate section (4).
摘要:
A method of detecting a level of printable fluid in a container includes, with at least one sensing location on a die in thermal contact with the printable fluid in the container, sensing a voltage of a capacitor over time as current from the capacitor leaks through a field effect transistor (FET). The FET and capacitor are associated with the sensing location. The method may further include, based on the voltage of the capacitor over time and a threshold voltage, determining whether the printable fluid is present at the at least one sensing location.
摘要:
The present invention is related to a sensor (20) for measuring the thickness of a layer (19) of a grain/residue mixture as the layer is transported through the cleaning arrangement of a combine harvester. The sensor is preferably mounted on the support surface of a grain pan or a sieve of the cleaning arrangement and comprises a tower-shaped support structure (21) with sensor elements (22) attached to the structure and forming a vertical stack of sensor elements, so that a number of sensor elements is submerged in the advancing layer (19) and a number of sensor elements extend above the layer. The sensor elements are configured to measure an electrical property that changes as a function of the immediate surroundings of the sensor element. The sensor elements (22) are configured to be read out independently from each other.
摘要:
The invention relates to a capacitive fill level sensor (10) for measuring the fill level (H1, H2; &EEgr;1', H2') of a medium (18) in a container (14), having an electrode unit (12), which contains a strip-shaped measurement electrode (22), a strip-shaped counter electrode (24) and a strip-shaped shielding electrode (26, 28, 40), the shielding electrode (26, 28, 40) at least partially surrounding the measurement electrode (22). The capacitive fill level sensor (10) according to the invention is characterised in that a first AC voltage source (60) having a predefined frequency and amplitude is provided, to which the shielding electrode (26, 28, 40) is connected such that a shielding capacitor (54, 56, 58) formed between the shielding electrode (26, 28, 40) and the measurement electrode (22) has a shielding capacitance that is proportional to the length of the shielding electrode (26, 28, 40), that a second AC voltage source (68) of equal frequency and a predefined second amplitude is provided, the second amplitude being in phase opposition to the first amplitude, to which AC voltage source the counter electrode (24) is connected, such that a measurement capacitor (52) formed between the counter electrode (24) and the measurement electrode (22) has a measurement capacitance that is proportional to the fill level (H1, H2; &EEgr;1', H2'), and that the measurement electrode voltage (72) present at the measurement electrode (22) is used to determine the fill level (H1, H2; &EEgr;1', H2').
摘要:
This invention relates to a device and method for measuring the depth of water and sediment deposition in pipes, channels, overland flows and tidal beaches. Sediment deposition may be detrimental to flood control in sewer systems. The invention is specifically concerned with measuring an electrical property such as the conductivity or capacitance in different mediums and therefore quantifying the depths of the different mediums. The measurement of an electrical property such as conductance or capacitance of the medium may also indicate the nature of the medium such as sediment structure, water salinity, and the presence of pollutants. The device includes an array of elongate, substantially mutually parallel electrodes each having a predetermined length, the lengths being incremented stepwise from a shortest electrode to a longest electrode. The device includes electronic circuitry to apply a potential difference across selected pairs of electrodes and to measure a resulting electrical property between each selected pair of electrodes, the measured electrical property providing an indication of a submersion depth of the pair of electrodes in the at least one medium.
摘要:
A level sensing apparatus including an antenna structure having an active component to which an electrical signal is applied during use, and a reference component. A controller causes the electrical signal to be applied to the antenna structure and monitors the electrical characteristics of the antenna's electrical circuit. The controller causes the apparatus to switch between first and second modes of operation by causing as witch to connect the reference component to, or isolate it from, the electrical circuit.
摘要:
Method for automatically, with the aid of a processor, determining a surface degeneration of a first surface of a urine handling system, the first surface being intended to come into contact with urine, the method comprises the following main steps: a) repeatedly measuring one or more capacitive values of the first surface, forming capacitive measurements; b) storing all, or representative instants of the capacitive measurements; c) deciding, based on changes of the stored capacitive measurements, that a significant surface degeneration of the first surface has occurred
摘要:
A gas-flow cryostat adapted for dynamic temperature regulation using a fluid level sensor; the cryostat further including one or more heaters coupled to various components of the cryostat. As fluid evaporates from a liquid coolant evaporation reservoir within the cryostat, the fluid level sensor and a feedback control module are adapted to monitor and dynamically control the level of evaporating coolant by regulating the heaters. Accordingly, the cryostat is adapted to dynamically control temperature about a specimen region within the cryostat. The cryostat can be used in various applications, including analytical laboratory equipment for measuring various physical properties of samples. Temperature sensors are further incorporated for added control and optimization of the cryostat.