Disclosed are a high-precision resistance measurement system and method combining a micro-differential method and a ratiometric method. The system includes a constant-current source, a reference resistor, a first differential amplifier, a programmable gain amplifier (PGA), an ADC, a microprocessor, a DAC and a to-be-measured resistor interface. The reference resistor and a to-be-measured resistor are connected in series between the constant-current source and ground. The voltage across the reference resistor is inputted to the first differential amplifier, and the output of the first differential amplifier is used as the reference voltage for the ADC and the DAC. The single-ended voltage to ground of the to-be-measured resistor and the output voltage of the DAC are inputted to the PGA in differential manner, and the PGA outputs the amplified difference voltage to the ADC. The output terminal of the ADC and the input terminal of the DAC are both connected to the microprocessor.

A device for determining the electrical resistance of a system includes a field effect electron emitter capable of emitting electrons when the electrical emission potential V.sub.e of the electron emitter is higher than a threshold value V.sub.L, with the emitting end of the emitter being at least partially conductive; an item of equipment capable of determining the electrical emission potential V.sub.e of the electron emitter; a voltage source adapted to apply a potential difference E to the device and to generate an electric field at the emitter, an electron detector capable of detecting all or some of the electrons emitted by the electron emitter so as to measure the intensity of the current I.sub.mes flowing between the emitter and the detector; electrical connection means adapted to electrically connect the system and the device in such a way that the current intensity flowing between the emitter and the detector can also pass through the system.

Aspects of the present disclosure are directed to a measurement module for measurement of a multi-electrode resistive sensing element with improved noise performance and accuracy. In some embodiments, stimulation to the sensing element is provided by a current path that originates from a signal source, through a switch block, through a pair of terminals, and ending at a reference node such as ground. An analog-to-digital converter (ADC) is coupled directly to one or both of the terminals to digitize a voltage. The ADC is coupled to terminals on the sensing element to measure a sensed voltage signal before the sensed signal goes through the switch block. As a result, the measured voltage signal may be free of noise that could be picked up from passing through the switch block, and accuracy of the resistance measurements on the sensing element can be improved.

Aspects of the present disclosure are directed to a measurement module for measurement of a multi-electrode resistive sensing element with improved noise performance and accuracy. In some embodiments, stimulation to the sensing element is provided by a current path that originates from a signal source, through a switch block, through a pair of terminals, and ending at a reference node such as ground. An analog-to-digital converter (ADC) is coupled directly to one or both of the terminals to digitize a voltage. The ADC is coupled to terminals on the sensing element to measure a sensed voltage signal before the sensed signal goes through the switch block. As a result, the measured voltage signal may be free of noise that could be picked up from passing through the switch block, and accuracy of the resistance measurements on the sensing element can be improved.

The invention provides a semiconductor testkey pattern, the semiconductor testkey pattern includes a high density device region and a plurality of resistor pairs surrounding the high density device region, wherein each resistor pair includes two mutually symmetrical resistor patterns.

The invention provides a semiconductor testkey pattern, the semiconductor testkey pattern includes a high density device region and a plurality of resistor pairs surrounding the high density device region, wherein each resistor pair includes two mutually symmetrical resistor patterns.

The present application discloses a circuit and a method for detecting insulation resistance. The circuit includes: a first voltage dividing module, a second voltage dividing module, a third voltage dividing module, a fourth voltage dividing module, a first switch module, a fifth voltage dividing module, a second switch module, a third switch module, and a detecting module, where the first voltage dividing module comprises a first voltage dividing unit and a second voltage dividing unit, and the third voltage dividing module comprises a third voltage dividing unit and a fourth voltage dividing unit. According to the embodiments of the present application, errors caused by fluctuations in the pull-up of the reference power supply can be avoided, and the accuracy of the circuit for detecting insulation resistance can be effectively improved.

The present application discloses a circuit and a method for detecting insulation resistance. The circuit includes: a first voltage dividing module, a second voltage dividing module, a third voltage dividing module, a fourth voltage dividing module, a first switch module, a fifth voltage dividing module, a second switch module, a third switch module, and a detecting module, where the first voltage dividing module comprises a first voltage dividing unit and a second voltage dividing unit, and the third voltage dividing module comprises a third voltage dividing unit and a fourth voltage dividing unit. According to the embodiments of the present application, errors caused by fluctuations in the pull-up of the reference power supply can be avoided, and the accuracy of the circuit for detecting insulation resistance can be effectively improved.

A method of determining the electrical resistance of an actual harness connecting the Engine Control Unit (ECU) to a solenoid valve. The method includes providing a dummy harness connected at one end to the ECU and at the other end to a terminal connection in the vicinity of the solenoid valve. The method also includes determining the estimated RMS current through the actual harness and passing a current through the dummy harness such that the heat exchange to the environment is substantially the same as the actual harness. Power consumption of the dummy harness is measured and resistance of the actual harness is determined from estimated RMS and power consumption of the dummy harness.

A method of determining the electrical resistance of an actual harness connecting the Engine Control Unit (ECU) to a solenoid valve. The method includes providing a dummy harness connected at one end to the ECU and at the other end to a terminal connection in the vicinity of the solenoid valve. The method also includes determining the estimated RMS current through the actual harness and passing a current through the dummy harness such that the heat exchange to the environment is substantially the same as the actual harness. Power consumption of the dummy harness is measured and resistance of the actual harness is determined from estimated RMS and power consumption of the dummy harness.