摘要:
A photoelectric sensing unit, especially useful for determining the passage of clear bottles or other low contrast targets on a conveyor, contains two sensors and a signal processing unit to determine the signal differential. The signal differential is compared to a selected value and sensor output is enabled or disabled. High noise immunity, resistance to target reflection, and output reliability result. The unit may correct the selected value to account for environmental change and/or unit component performance. The unit can also figure the speed of passage of the bottles.
摘要:
A light curtain device for creating a curtain of light between a reflective first location and a second location is disclosed. The device includes a light source adapted to provide a light column, a plurality of beam splitters, a plurality of light detectors, and an indicator arranged to indicate the interruption of the light column. The beam splitters are disposed to intersect the light column at intervals, and each of the beam splitters is adapted to direct a deflected portion of the light column toward the first location. The reflective first location receives the deflected portion of the light column from each of the beam splitters and reflects each deflected portion toward the second location. The light detectors are disposed adjacent the second location, with each of the light detectors being operatively associated with a corresponding one of the beam splitters and being positioned to the receive its corresponding deflected portion reflected by the reflector.
摘要:
A photodetector is provided with two light sources and a light sensitive component. The use of two light sources significantly reduces the opportunity of a surface feature, or abnormality, from focusing light back toward the light sensitive component in a manner that could possible cause the photodetector to misinterpret the intensified light as being indicative of the absence of an object in the detection zone. The light sources and light sensitive component can be arranged along an axis which is either parallel to the path of the objects to be detected or perpendicular to their path.
摘要:
A detector, such as a photodetector, is provided with a serial output and serial input capability so that a first plurality of pulses can be transmitted from the detector in a first preselected direction. The first plurality of pulses represent a coded pattern. When pulses are received by the receiver portion of the detector, the received second plurality of pulses is compared to the first plurality of pulses to determine whether or not the two pluralities of pulses represent precisely matched coded patterns. The use of coded patterns that comprise a plurality of bits, or pulses, significantly decreases the chance of a mis-identification of a received pulse as being representative of a reflected transmitted pulse.
摘要:
An interface circuit for interfacing a data bus with a current sinking sensor or a current sourcing sensor. An input terminal is connected between a cathode of a first diode and an anode of a second diode. The anode of the first diode is connected to a first input terminal of a comparator, such as a differential amplifier. The cathode of the second diode is connected to a second input of the comparator. Two pairs of in-series resistors are connected between a voltage supply. The anode of the first diode is connected between two resistors of the first pair of resistors. The cathode of the second diode is connected between two resistors of the other pair of resistors. An output of the comparator is connected to an output terminal. The interface circuit of this invention can be connected between an input circuit and an output circuit, to interface a sensor parameter and the corresponding input current or signal to the data bus and a corresponding output current or signal.
摘要:
A wireless surface wave flow sensor can be utilized for monitoring the flow of fluid. Such a surface wave flow sensor can be configured to include one or more interdigital transducers and a self-heating heater formed upon a piezoelectric substrate. The interdigital transducer(s) can be selected to convert electrical signals to surface waves thereof. An antenna can also be connected to the surface wave device, wherein the antenna can receive one or more signals, which excites the acoustic device to produce a frequency output associated with the flow of the fluid for analysis thereof.
摘要:
A disposable fluid flow sensor is disclosed herein, which generally includes a flow channel assembly comprising a flow channel tube in association with a disposable flow channel portion. A sensor die is located approximate to a thin interface or membrane formed from the disposable flow channel portion, such that the sensor die measures a flow of fluid flowing through the flow channel tube and the disposable flow channel portion of the flow channel assembly. Additionally, a substrate can be provided upon which the sensor die is formed and located. A seal can also be provided for sealing the disposable flow channel portion to the flow channel tube. Such a flow sensor can be implemented in the context of a “non-isolated” sensor die approach in which the sensor die, substrate and flow tube are assembled together into a complete disposable assembly, in which a thin interface does not cover the sensor die. The flow sensor can also be implemented in the context of an “isolated” sensor die approach in which a thin membrane material or thin interface prevents the fluid from touching the surface of the sensor die. In such an “isolated” configuration, the sensor die is not actually part of the disposable flow tube assembly. The only disposable portion in this approach is the flow tube itself.
摘要:
A sensor method and system are disclosed. A fluid flow sensor can be provided, which measures the thermal conductivity of a fluid. The sensor itself can be configured to comprise one or more sensing element associated with a sensor substrate. A heater can be associated with said sensor wherein said heater provides heat to said fluid. A film component can also be provided that that isolates said fluid from said heater and said sensor, such that said film component conducts heat in a direction from said heater to said sensor, thereby forming a thermal coupling between said sensor, said heater and said fluid, which permits said sensor to determine a composition of said fluid by measuring thermal conductivity thereof without undesired losses of heat in other directions. The film component can be configured on or in the shape of a tubing or a flow channel.
摘要:
A high-sensitivity carbon monoxide sensor is shown and described. The sensor includes a sensing element having a catalyst dispersed over a metal oxide layer. The catalyst is capable of adsorbing carbon monoxide. The sensing element can also include a heater and a temperature sensor. A flow sensor is provided for sensing a flow rate of gas directed at the sensing element. The signal processing module is coupled to the flow sensor and the temperature sensor. A flow sensor sends signals indicative of the flow rate to the processing module while the temperature sensor sends signals indicative of the temperature of the sensing element to the processing module. After carbon monoxide has been adsorbed onto the catalyst and metal oxide layer for a fixed time period, the heater is activated to heat the sensing element above the light-off temperature or at least as high as the oxidation temperature of the adsorbed carbon monoxide. As a result, an exothermic oxidation of the adsorbed carbon monoxide takes place, which results in an increase in the temperature of the sensing element. This increase in the temperature of the sensing element is used to determine the amount of accumulated adsorbed carbon monoxide which, in conjunction with the flow rate and the fixed time period, is used to calculate the carbon monoxide concentration in the gas flow.
摘要:
A carbon monoxide sensor and method is shown and described. The sensor includes a sensing element that includes an adsorbent dispersed over a support material. The adsorbent is capable of exothermically adsorbing carbon monoxide. The sensor also includes a temperature sensor in contact with the sensing element and a signal processing module coupled to the temperature sensor. The temperature sensor communicates signals indicative of a temperature increase of the sensing element to the processing module, thereby indicating an adsorption and, therefore, a presence of carbon monoxide.