Abstract: A power on/off control circuit and an electronic device is provided, the circuit including: a switching element, a first semiconductor switching circuit including a first semiconductor switching element, a second semiconductor switching circuit including a second semiconductor switching element, and a holding circuit connected between a first terminal of the first semiconductor switching element and a second terminal of the second semiconductor switching element. When the switching element is closed, the first semiconductor switching element is turned on. When the first semiconductor switching element is turned on, the second semiconductor switching element is turned on, and a power on signal is output via the second terminal of the second semiconductor switching element. When the second semiconductor switching element is turned on, the holding circuit is operable to maintain the on state of the first semiconductor switching element. The control circuit can stably lock a started state.

Abstract: A sensing device with a sealing structure for measuring fluid characteristics by a photoelectric method is disclosed. The sensing device includes an electrode head having an outer side which contacts a fluid to be measured and one or more windows arranged in respective window openings which extend between an inner and an outer face of a wall of the electrode head. At least two sealing structures seal the one or more windows and the respective window openings. A first of the at least two sealing structures is bonded, welded, or provides an interference fit. The sensing device can be used to seal the product in high temperature, high pressure, and corrosive environment, so that the product has high air tightness and is stable and reliable for a long time. In addition, the sealing structure of the product is easy to clean.

Abstract: A low-power electronic pipette has a charging management module (10), a control module (20), a motor driving module (30), a display module (40), a communication module (50), a sensing module (60), and a battery module (70). The charging management module, the communication module, and the sensing module are each in two-way communication with the control module. The display module and the motor driving module are each in one-way communication with the control module. The battery module supplies energy to the low-power electronic pipette. When the sensing module acquires a signal and determines that the low-power electronic pipette has not been operated for a predetermined period and is not in a charging state, the low-power electronic pipette enters a low-power mode, in which the control module turns off the charging management module, the motor driving module, the display module, and the communication module, and the control module enters a sleep state.

Abstract: An optical structure has a cavity (1) with an opening provided at one end and a first through hole or first gap (21) provided at the end opposite the opening. The cavity is further provided internally with a beam splitter or a dichroic mirror (4). A first LED (31) emits light into the cavity through the first through hole or the first gap, which passes directly passing through the beam splitter or dichroic mirror and exits from the opening of the cavity A second LED (32) emits light into the cavity through a second through hole or second gap (22) in a side of the cavity, which is reflected by the beam splitter or dichroic mirror. It is then fused with the light emitted by the first LED. The light emitted by the respective LEDs have an identical optical path length to the beam splitter or the dichroic mirror.

Abstract: An optical structure has a cavity (1) with an opening provided at one end and a first through hole or first gap (21) provided at the end opposite the opening. The cavity is further provided internally with a beam splitter or a dichroic mirror (4). A first LED (31) emits light into the cavity through the first through hole or the first gap, which passes directly passing through the beam splitter or dichroic mirror and exits from the opening of the cavity A second LED (32) emits light into the cavity through a second through hole or second gap (22) in a side of the cavity, which is reflected by the beam splitter or dichroic mirror. It is then fused with the light emitted by the first LED. The light emitted by the respective LEDs have an identical optical path length to the beam splitter or the dichroic mirror.

Abstract: An apparatus and method for measuring the horizontal position uses a gas bubble in a bubble level. The gas bubble is in a cylindrical sealed housing that is partially filled with liquid. At least two light-emitting devices are used to illuminate the gas bubble and an inner bottom surface of the bubble level. A corresponding number of receiving devices are used to receive the light that is either reflected by the inner bottom surface or is reflected and refracted by the gas bubble. The amount of light received is translated into an electrical signal and is sent to a processing unit to calculate the position of the gas bubble. The light-emitting devices and the receiving devices are disposed in an alternating manner at the periphery of the cylindrical sealed housing.

Abstract: An apparatus and method for measuring the horizontal position uses a gas bubble in a bubble level. The gas bubble is in a cylindrical sealed housing that is partially filled with liquid. At least two light-emitting devices are used to illuminate the gas bubble and an inner bottom surface of the bubble level. A corresponding number of receiving devices are used to receive the light that is either reflected by the inner bottom surface or is reflected and refracted by the gas bubble. The amount of light received is translated into an electrical signal and is sent to a processing unit to calculate the position of the gas bubble. The light-emitting devices and the receiving devices are disposed in an alternating manner at the periphery of the cylindrical sealed housing.

Abstract: An exemplary method for measuring the electrical resistance and/or electrical conductivity of solutions, includes: exciting the electrodes with a rectangular shaped, alternating current of a certain frequency fH through a connecting cable; synchronously rectifying a voltage of the electrodes of the measuring cell in response to the alternating current, calculating a first average voltage, dividing the first average voltage by the current amplitude to obtain a first impedance RH; then exciting the electrodes with a rectangular shaped, alternating current of another frequency fL through the connecting cable; synchronously rectifying the voltage of the electrodes in response to the alternating current, calculating a second average voltage, and dividing the second average voltage by the current amplitude to obtain a second impedance RL.

Abstract: Exemplary embodiments of the present invention are directed to methods and devices for detecting open-circuit and short-circuit failure in an electromagnetic (inductive) measurement of the conductivity of liquids and on the sensor and cable wiring. An electromagnetic measurement of the conductivity of a liquid is performed by immersing a sensor into the liquid, wherein the sensor includes at least 2 toroidal cores, one of them carrying an excitation coil and the other carrying an induction coil. When an AC excitation voltage is applied to the excitation coil, an induced current or voltage can be measured in the induction coil which is proportional to the conductivity of the measured liquid.

Abstract: Exemplary embodiments of the present invention include methods and devices for the electromagnetic (inductive) measurement of the conductivity of liquids by immersing a sensor into the liquid, wherein the sensor includes at least 2 toroidal cores, one of said cores carrying an excitation coil and the other core carrying an induction coil. Exemplary methods include converting the induced current at the induction coil into an alternating square-wave voltage, followed by rectification. A sample-hold circuit may be employed to avoid the transition time of the alternating square-wave current conversion. The demodulated DC voltage is proportional to the conductivity of the measured liquid.

Abstract: Exemplary embodiments of the invention include an input circuit for electromagnetic (inductive) measurements of the conductivity of liquids. The input circuit and the induction coil are directly coupled, and the arrangement includes a current-voltage converting circuit which accomplishes the transformation from current to voltage in the induction coil, and ensures the terminal voltage to be zero. Also there is an anti-saturation circuit which is composed of an integrating circuit and a voltage dividing circuit and serves to prevent saturation in the operational amplifier which is used for the current-voltage transformation. The circuit further includes features for the detection of an open-circuit failure of the sensor coil or cable.

Abstract: A method and device are disclosed for measuring potentiometric measuring probes. An exemplary method includes feeding two test voltages comprising a harmonic wave Ueg with a base frequency fg and the harmonic wave Uer with a base frequency fr into two cores of a connecting cable through voltage source impedances, respectively. The voltage between an indicating electrode and a reference electrode, and the AC responding signal resulting from the two test voltages are passed to an amplifier and further to a transfer function unit having transfer functions (Hg, Hr), an A/D converter, and a Fourier transformation unit, to calculate a potential Ux and the two test responses Ug and Ur, respectively. Two calibration responses Uehg and Uehr are determined, wherein Uehg includes a product of Ueg and Hg, and wherein Uehr includes a product of Uer and Hr.

Abstract: Exemplary embodiments of the present invention are directed to methods and devices for detecting open-circuit and short-circuit failure in an electromagnetic (inductive) measurement of the conductivity of liquids and on the sensor and cable wiring. An electromagnetic measurement of the conductivity of a liquid is performed by immersing a sensor into the liquid, wherein the sensor includes at least 2 toroidal cores, one of them carrying an excitation coil and the other carrying an induction coil. When an AC excitation voltage is applied to the excitation coil, an induced current or voltage can be measured in the induction coil which is proportional to the conductivity of the measured liquid.

Abstract: Exemplary embodiments of the invention include an input circuit for electromagnetic (inductive) measurements of the conductivity of liquids. The input circuit and the induction coil are directly coupled, and the arrangement includes a current-voltage converting circuit which accomplishes the transformation from current to voltage in the induction coil, and ensures the terminal voltage to be zero. Also there is an anti-saturation circuit which is composed of an integrating circuit and a voltage dividing circuit and serves to prevent saturation in the operational amplifier which is used for the current-voltage transformation. The circuit further includes features for the detection of an open-circuit failure of the sensor coil or cable.

Abstract: Exemplary embodiments of the present invention include methods and devices for the electromagnetic (inductive) measurement of the conductivity of liquids by immersing a sensor into the liquid, wherein the sensor includes at least 2 toroidal cores, one of said cores carrying an excitation coil and the other core carrying an induction coil. Exemplary methods include converting the induced current at the induction coil into an alternating square-wave voltage, followed by rectification. A sample-hold circuit may be employed to avoid the transition time of the alternating square-wave current conversion. The demodulated DC voltage is proportional to the conductivity of the measured liquid.

Abstract: An exemplary temperature measurement device includes a reference voltage source, a three-wire thermal resistor, a voltage drop amplifier, an operational amplifier and compensation resistors. By using connecting wires with resistance values of the compensation resistors, a relation between an output signal and a resistance of the thermal resistor gives rise to a monotonous function, which is independent of the resistances of the connecting wires. After A/D conversation of an output signal, the resistance of the thermal resistor and a temperature can be calculated based on known functions. Therefore, within an entire measurement range and any length of cable, an influence of the wire resistances can be compensated without switches or jumpers.

Abstract: A method and device are disclosed for measuring potentiometric measuring probes. An exemplary method includes feeding two test voltages comprising a harmonic wave Ueg with a base frequency fg and the harmonic wave Uer with a base frequency fr into two cores of a connecting cable through voltage source impedances, respectively. The voltage between an indicating electrode and a reference electrode, and the AC responding signal resulting from the two test voltages are passed to an amplifier and further to a transfer function unit having transfer functions (Hg, Hr), an A/D converter, and a Fourier transformation unit, to calculate a potential Ux and the two test responses Ug and Ur, respectively. Two calibration responses Uehg and Uehr are determined, wherein Uehg includes a product of Ueg and Hg, and wherein Uehr includes a product of Uer and Hr.

Abstract: An exemplary method for measuring the electrical resistance and/or electrical conductivity of solutions, includes: exciting the electrodes with a rectangular shaped, alternating current of a certain frequency fH through a connecting cable; synchronously rectifying a voltage of the electrodes of the measuring cell in response to the alternating current, calculating a first average voltage, dividing the first average voltage by the current amplitude to obtain a first impedance RH; then exciting the electrodes with a rectangular shaped, alternating current of another frequency fL through the connecting cable; synchronously rectifying the voltage of the electrodes in response to the alternating current, calculating a second average voltage, and dividing the second average voltage by the current amplitude to obtain a second impedance RL.

Abstract: An exemplary temperature measurement device includes a reference voltage source, a three-wire thermal resistor, a voltage drop amplifier, an operational amplifier and compensation resistors. By using connecting wires with resistance values of the compensation resistors, a relation between an output signal and a resistance of the thermal resistor gives rise to a monotonous function, which is independent of the resistances of the connecting wires. After A/D conversation of an output signal, the resistance of the thermal resistor and a temperature can be calculated based on known functions. Therefore, within an entire measurement range and any length of cable, an influence of the wire resistances can be compensated without switches or jumpers.