363results about "Ac/dc potentiometric measuring arrangements" patented technology

Reactive sensors typically exhibit nonlinear response to the combination of an excitational signal (e.g., sinusoidally oscillating signal) and a physical parameter under measure (e.g., position of magnetic core member). Such sensors are typically sensitive to temperature variation. Systems and methods are disclosed for compensating for the nonlinear and / or temperature dependant behavior of reactive sensors and for calibrating the post-compensation output signals relative to known samples of the physical parameter under measure (e.g., position). One class of embodiments comprises a housing containing at least part of a reactive sensor, a monolithic integrated circuit and a timing reference (e.g., an oscillator crystal). The integrated circuit includes a waveform generator for generating a sensor exciting signal, a detector for detecting the response of the sensor to the combination of the exciting signal and the under-measure physical parameter, a temperature compensating unit and a Pade' Approximant based, nonlinearity compensating unit. The temperature compensating unit and the Pade' Approximant nonlinearity compensating unit are tuned by use of digitally programmed coefficients. The coefficients calibrate the final output as well as compensating for nonlinearity and temperature sensitivity. A highly accurate measurement of the under-measure physical parameter is made possible even though each of the sensor and compensating circuitry may be relatively simple, compact, and low in cost.

A method and system for calibrating an analog sensor used in a digital measurement system is provided. The design comprises generating a precise pressure value set at multiple calibration points and supplying said precise pressure value set to an uncalibrated pressure sensor, detecting sensor changes for the uncalibrated pressure sensor based on each precise pressure value generated, polling an actual pressure reading associated with a sensor change for the uncalibrated pressure sensor for each calibration point, and establishing a mathematical relationship between measured value readings and actual pressure for the uncalibrated sensor. Establishing the mathematical relationship converts the uncalibrated sensor to a newly calibrated sensor. A known good sensor may be employed to enhance calibration reliability.

Reactive sensors typically exhibit nonlinear response to temperature variation. Systems and methods are disclosed for compensating for the nonlinear and / or temperature dependent behavior of reactive sensors and for calibrating the post-compensation output signals relative to known samples of the physical parameter under measure. One call of embodiments includes a housing containing at least part of a reactive sensor, a monolithic integrated circuit and a timing reference. The integrated circuit includes a waveform generator for generating a sensor exciting signal, a detector for detecting the response of the sensor to the combination of the exciting signal and the under-measure physical parameter, a temperature compensating unit and the Pade Approximant nonlinearity compensating unit are tuned by use of digitally programmed coefficients. The coefficients calibrate the final output as well as compensating for nonlinearity and temperature sensitivity.

A circuit and a method to measure continuously the resistance of variable resistors in series as e.g. potentiometers within a sensor, used for e.g. a joystick, has been achieved. The voltage across said sensor comprising any number of variable resistors is stabilized. A constant current source is providing a minimum current through said sensor. A variable current source is used to zoom variations of current through the sensor caused by variations of resistance of the sensor. Said variable current is mirrored and by measuring the voltage across a shunt resistor the total resistance of the sensor is identified. Using ports between each of the resistors, voltages can be measured representing the resistance of each of the variable resistors using known equations of voltage dividers. Any number of variable resistors can be used in the circuit invented.

The present invention discloses a method of using of a programmable circuit to calibrate a transducer. The programmable circuit is coupled to or communicates with a computer and to a testing station. The computer automatically varies the conditions of the testing station and programs the programmable circuit to produce a desired response. In another embodiment, a system is presented that can be used to measure various parameters that includes a programmable that may be mounted in the same package as a sensor. Such a system may include pressure sensors that are optimized to measure very low pressures.

A driving device, includes a stepping motor having an exciting coil and a rotor; a driven member driven in accordance with a rotation of the rotor; a stopper mechanically stopping the driven member at a zero position; a controller controlling the state of excitation of the exciting coil; an induced voltage detector detecting an induced voltage generated by a change of magnetic flux according to the rotation of the rotor; and a zero position detector detecting a stoppage of the driven member at the zero position. The controller supplies an exciting pattern to the exciting coil at the time of processing of zero position detection. The exciting pattern includes a first exciting step for detecting the induced voltage and a second exciting step for rotation. Total periods of the first exciting step is greater than that of the second exciting step during an electrical angle 90° in the one cycle.

A method of calibrating a metabolic analyzer incorporating an oxygen analyzer and a NDIR carbon dioxide analyzer in the field that does not require the use of gas cylinders containing gases of known concentration is described. In calibrating the CO2 detector, at the time of factory setup, the detector output for a gas of a known concentration is measured and stored in the memory of the metabolic analyzer's microprocessor, as is the detector output voltage when the IR source is dimmed by a known percentage. Subsequently, in the field, CO2 levels in ambient air and cell pressure are measured at two different flow rates through the sample chamber and the IR source is again dimmed by the same percentage as had been used at the time of factory setup. Based upon the resulting readings, both the zeroing and span adjustment factors can be computed.

The portable potential difference meter for high resolution measurement of DC voltage consists of work loop, standard loop and measurement loop. Its measurement loop has three measurement discs connected directly with wires, and no switch contact resistance and its variation. The measurement circuit has no influence of thermal potential, so that the portable potential difference meter has resolution as high as 0.1 microvolt.

The invention provides a potentiometer for measuring direct current voltage. The potentiometer comprises four step panels and a double wire sliding panel, the five panels consist of a measurement panel and a substitution panel with the same resistance value, working current is divided into two branches with the ration of ten to one between two electric brushes in the first step panel, and two panels of each branch are in parallel connection and have the same current; except the first step panel, electric brushes of measurement panels of other four step panels and the electric brush of the substitution panel are connected by resistors or conducting wires, neither each step panel nor the double wire sliding panel is provided with a bracket panel, thus the size of the instrument is reduced and the production cost is reduced. Meanwhile, the five measurement panels are connected through conducting wires, so the influence from deviation and thermoelectricity is eliminated.

An engine exhaust emission control device determines a differential pressure across a diesel particulate filter (DPF) to enable regeneration of the DPF at optimal timing. An ECU estimates the temperature of a differential pressure sensor provided for the DPF from the output of an intake air temperature sensor when the engine is not running, and determines an offset correction factor for correcting the sensor's offset error. The factor is set using the sensor output at this time as sensor's offset error, and stored in a memory. When detecting the differential pressure across the DPF, the temperature of the sensor at this time is estimated, and an offset correction factor that corresponds to this estimated temperature is selected. The sensor outputs are adjusted with this offset correction factor.

The device is constructed to position a measuring sensor, especially a sensor head at an angle to a sensor shaft, precisely at the point of measurement and in the direction of a fluid flowing in a test tube, in which there is an adjuster through which the measuring sensor, in a coaxial arrangement, can be adjusted via a first adjusting motor about its axis and / or by a second adjusting motor along its axis. A control device communicates with an electronic computer for controlling the sensor adjustment. An adjuster (4) is coupled to the sensor to rotate in unison therewith and has a rotatable pendulum which, in the position of rest transversely to the test tube axis defines the zero position of the sensor. Limit positions of the pendulum are predetermined from a relative movement of the adjuster about the axis which can be photometrically converted into position signals. The computer mathematically halves the angular adjustment calculated from the position signals received and sets the adjuster with the sensor to mechanical zero by the respective positioning stop command signals.

A sensor incorporates a dual range ASIC (Application Specific Integrated Circuit) for accurately sensing and measuring sensor input over extensive range along with an improved resolution. The sensor can incorporate an ASIC utilizing signals from a MEMS-based piezoresistive Wheatstone bridge. Signals can also come from capacitive pressure measurement sources. The signals can be converted to digital bit counts where calibration coefficients can be implemented to achieve high precision. The calibration coefficients corresponding to bit counts can be compared with transition points that are recorded into ASIC for effectively distinguishing different sensor ranges. The transition points can be stored in an EEPROM fabricated to suit ASIC applications.

A two-range DC potential difference meter is composed of two ranges and four measuring plates of 20*8 omega, 10*0.88 omega, 9*1.76omega.and 10*0.176 omega .It features that all measuring resistances are directly connected by wires to exclude variation and contact resistance of measuring-stepping switch from measuring result and range conversion resistance value is integer power of one digit being multiplied by ten.

A resolver output correction device receives sine output signal and cosine output signal from a resolver. Each of the sine output signal and the cosine output signal has an offset error and a gain differential error due to a secular variation. The correction device detects maximal and minimal values with respect to both the sine output signal and the cosine output signal. It calculates average values between the maximal values and the minimal values. Then, it corrects the offsets of the signals based on the average values. It also calculates gain differentials between the maximal value and the minimal value with respect to both the sine and cosine signals. Then, it corrects the gain differentials of the signals based on the calculated gain differentials. As a result, both the offset and gain errors of the signals are corrected with accuracy.

Zero and calibration drift errors in a magnetic flow meter can be detected and automatically corrected. A zero error can be detected by measuring an amplifier output when the meter's electromagnet is inactive. Automatic calibration of the span can be done by adding a signal to a measured electrode voltage at an amplifier input, subtracting the expected amplified value of that signal at the output and adjusting the amplifier gain responsive to the difference in signal magnitude.

The process of invention provides a simplified conversion of sulfur dioxide gas into hydrogen sulfide gas. First, sulfur dioxide gas is absorbed into an aqueous sulfide solution to form sulfite and bisulfide ions. Second, additional sulfur dioxide gas is absorbed into the aqueous solution to form hydrogen sulfide. Third, another portion of the sulfur dioxide is absorbed and reacts in the aqueous solution to form bisulfite. Most advantageously, the bisulfite is decomposed into sulfur dioxide and sulfite. The sulfite is then reduced to sulfide and returned for use in the absorption process. The hydrogen sulfide may then be reacted with SO2 via the Claus reaction to form elemental sulfur.

The present invention discloses a method of using of a programmable circuit to calibrate a transducer. The programmable circuit is coupled to or communicates with a computer and to a testing station. The computer automatically varies the conditions of the testing station and programs the programmable circuit to produce a desired response. In another embodiment, a system is presented that can be used to measure various parameters that includes a programmable that may be mounted in the same package as a sensor. Such a system may include pressure sensors that are optimized to measure very low pressures.

A driving device, includes a stepping motor having an exciting coil and a rotor; a driven member driven in accordance with a rotation of the rotor; a stopper mechanically stopping the driven member at a zero position; a controller controlling the state of excitation of the exciting coil; an induced voltage detector detecting an induced voltage generated by a change of magnetic flux according to the rotation of the rotor; and a zero position detector detecting a stoppage of the driven member at the zero position. The controller supplies an exciting pattern to the exciting coil at the time of processing of zero position detection. The exciting pattern includes a first exciting step for detecting the induced voltage and a second exciting step for rotation. Total periods of the first exciting step is greater than that of the second exciting step during an electrical angle 90° in the one cycle.

The present invention relates to a potentiometer, which is used for measuring the DC voltage and adopts the slip-line disc. The potentiometer consists of three stepping discs and a double-slip-line disc; the four discs all consist of a measuring disc and a replacing disc, which have the same resistance value; the working current is divided into two branches of 10 to 1 between two electrical brushes of the first stepping disc; two branches of the same current are formed in the branch with two parallel discs; the electrical brushes of the other measuring discs except the first stepping disc are connected with the electrical disc of the replacing disc through resistances or wires; each stepping disc or the double-slip-line disc has no auxiliary disc; therefore, the volume of the device is reduced, the manufacturing cost of the device is reduced, simultaneously the four measuring discs are connected through wires, and the influence of the variation and the thermoemf is eliminated.

An apparatus including: an optical sensor comprising an optical transmitter and an optical receiver; and a calibration system configured to change calibration of the sensor when a measurement taken at the optical receiver, while the optical transmitter is on and the apparatus is in use, passes a test.

The invention relates to a two-measuring-range potential difference meter with four metering panels, which is used for measuring direct-current voltage; four metering panels are directly connected by lead wires without a switch for switching, therefore, no contact resistance variation effect of the switch exists when the potential difference meter is used for measuring; the resistance value of the metering panel of each step panel and a substitution panel is 10 integer power, and the resistance can be compared with standard resistance by an electrical bridge, so as to improve the resistance manufacturing precision and improve the measuring accuracy of the whole potential difference meter.

A two-range switching potential difference meter with four measuring discs and applying distributary branch is composed of two ranges and four measuring discs as 20x 5 omega, 10x 0.55 omega, 9x 1.1 o mega and 10x 0.11 omega. It features that all measuring resistance are directly connected by conducting wire to exclude contact resistance and variation from measuring-stepping switch out of measuring result and integer power of one digit number multiplying by ten is used as value of resistance being used for range changeover.

The portable potential difference meter for the measurement of DC voltage consists of work current regulating resistor, setting resistor and measuring resistor. The setting resistor has resistance of 50 ohms and work current of 5.5 mA. One meter with pointer is used to indicate whether the voltage on the setting resistor is equal to the reference voltage of 275 mV, and voltage difference is amplified in the operation amplifier. The work current regulating resistor is used to regulate the work current to 5.5 mA. The instrument has three measurement ranges and maximum measured voltage of 2.3 V.

A method of correcting a pointing position of a pointer rotated by a stepper motor includes the steps of: performing a prereset operation in which the pointer is rotated to a reset operation starting position that represents a pointing position of the pointer which is shifted by a predetermined amount in a plus direction of a scale from a reset position where a pin which is rotated in conjunction with a rotation of the pointer abuts against a fixed stopper; after the prereset operation, performing a reset operation in which the pointer is rotated in a minus direction of the scale to the reset position; and after the reset operation, performing a correcting operation in which the pointer is rotated in the plus direction up to a reference pointing position which is indicated by previously stored reference pointing positional information.

An apparatus including: an optical sensor comprising an optical transmitter and an optical receiver; and a calibration system configured to change calibration of the sensor when a measurement taken at the optical receiver, while the optical transmitter is on and the apparatus is in use, passes a test.

An arrangement and method for providing compensation to a cyclical input signal is disclosed. The arrangement comprises a first detection unit (20) for detecting a first event in a cyclical output signal; a compensation signal generation unit (14) for generating a compensation signal; and a signal combination unit (8) for combining the compensation signal and the cyclical input signal to obtain the cyclical output signal. The compensation signal generation unit (14) is arranged to adjust the compensation signal at an instant which has a determined relationship with the detection of the first event. By adjusting the compensation signal at the right instant in a cycle of the cyclical output signal, the adjustment will not influence the further processing of the cyclical output signal. The method can be used to compensate the offset and sensitivity characteristics of a sensor.

A programmable liquid sampler for obtaining and digitally analyzing multiple, sequential samples in real time from an external source of liquid to be analyzed comprises an adaptive feedback algorithm for correcting sample weight measurements occasioned by vacuum delays. A sampling assembly receives and at least temporarily stores a sample drawn by suction through an air port that can also pressurize the chamber. A load cell determines sample mass through a logic controller that implements adaptive feedback by recognizing a desired target sample size, requesting an initial sample, and measuring the initial sample size. A variable scaling factor is derived by comparing the target sample size to said measured sample size and the subsequent requesting size is scaled. Samples can be stored in multiple compartments of a radial table that is indexed by the computer software for proper sample control.

A three¿C range potential difference meter with four measuring discs and applying conversion branch is composed of four measuring discs as 20x 10 omega, 10x 1.1 omega, 9x 2.2 omega and 10x 0.22 omega. It is featured as connecting all measuring resistances directly by conducting wire to exclude contact resistance and variation of measuring ¿C stepping switch out of measuring result, using integer power of one digit number or two digit number multiplying by ten as value of resistance used on range switch ¿C over.