Abstract: The phase response of a network is measured at uniform frequency intervals. A linear regression analysis is performed on samples of the phase response measured at frequencies within an aperture centered on a group delay frequency to obtain an estimate of the group delay of the network at that frequency. The process is repeated for a sequence of group delay frequencies to determine a trace of the group delay of the network across a range of frequencies.

Abstract: The breakdown of an ultra-thin dielectric layer is detected by applying a test signal to the layer. Measurements are taken of noise signals present in the layer during the application of the test signal. At breakdown, a significant increase occurs in the amplitude of the measured noise signals. Similarly, fluctuations in quiescent current, I.sub.DDQ, (I.sub.DDQ noise signals), rather than the values of I.sub.DDQ, are utilized during testing as the basis for detecting defects in integrated circuits.

Abstract: A portable diagnostic device for checking electrical signalling systems of school buses and/or tractor trailers. The device has several receptacles for connection to a corresponding receptacle or pin connector of a school bus and most types of trailers. One electrical circuit includes switches for energizing individual signalling or illumination circuits of the trailer individually, and indicating lamps for annunciating circuit operability. Another electrical circuit includes switches for energizing individual signalling or illumination circuits of the school bus individually, and indicating lamps for annunciating circuit operability. The device, which is contained on a wheeled cart, has its own power supply and circuit overcurrent protective devices, and is thus independent of a school bus and a tractor, both of which normally generate the signals. The device enables a shop to perform a safety check for many varieties of school buses and trailers.

Abstract: There is provided a detector for detecting conductive contaminants entrained in an airflow. The detector comprises first and second electrically conductive meshes mounted in a spaced apart relationship to provide an operational gap. Each of the meshes is sized to provide a relatively large surface for substantially intersecting the airflow and is sufficiently porous so as not to substantially attenuate the airflow. The meshes form part of an energizable electric circuit wherein the operational gap constitutes a discontinuity of the circuit. The detector includes a capacitor connected in parallel to the portion of the circuit containing the operational gap for releasing a charge stored in the capacitor through the circuit discontinuity when one of the conductive contaminants simultaneously contacts the first and second meshes. The detector further provides for indication of a discharge of the capacitor and thereby the presence of one of the airborne conductive contaminants entrained in the airflow.

Abstract: The present invention is a current sensing method and apparatus wherein a current transformer producing a secondary current is disposed in communication with a conductor having a primary current desired to be sensed. A current analyzer in communication with the current transformer is adapted to estimate the primary current in the conductor based on the secondary current output waveform, even in the case where the secondary current is in saturation. In one embodiment, the current analyzer estimates the primary current in the conductor by capturing the secondary current waveform output from the current transformer, selecting a predetermined number of data points in an undistorted, region of the secondary current waveform, and estimating the primary current based on the selected data points.

Abstract: Equipment under test is adjusted during set-up for electromagnetic compatibility testing. The equipment under test is placed on a base, such as a table, other structure or the ground. Positioners are connected to cables and/or subparts of the equipment under test. For example, the positioners are non-metallic pneumatic cylinders. The positioners are anchored to the base, to the device under test, or to some other structure. For various positions of an antenna relative to the equipment under test, positions of the positioners are found for which there is a maximum signal response. This is done by measuring signal response for current positions of the positioners. The current positions of the positioners are then varied using a remote control unit which controls positions of the positioners. This is repeated for as many different positions as desired. The positions which resulted in the maximum signal response is utilized for the electromagnetic compatibility testing.

Abstract: A measuring apparatus has a capacitor incorporated in a handy measuring tool electrically connected to a voltage meter, and a sharp leading end of the capacitor is brought into contact with a lead of a large scale integrated circuit device for accumulating movable electric charge induced in the presence of a charged insulating package into the capacitor so that the amount of the accumulated movable electric charge is calculated from a potential difference produced between electrodes of the capacitor.

Abstract: A method and an apparatus for testing compensated input/output buffers. In one embodiment, a compensated input/output buffer includes a node from which a plurality of compensation devices are coupled in parallel to a particular voltage level, such as for example V.sub.CC or ground. Compensation control signals are received by each one of the compensation devices such that the compensation signals are configured to selectively switch on and off each one of the plurality of compensation devices. An input/output test bus is coupled to the node and thus has access to each one of the compensation devices. Test circuitry is configured to selectively switch on and off each one of the compensation devices such that a switchable conductive path is formed from the node to the particular potential level through each one of the plurality of compensation devices.

Abstract: An on-line somatic cell analyser and a method for measuring a somatic cell count (SCC) are provided. A flow cell is connected to a milking hose and admits a constant volume of sampled milk into the flow chamber. A probe with two electrodes is positioned in a zone of optimal sensing inside the flow chamber, and provides a modulated signal according to the number of sodium ions present in the sample. A control unit receives the modulated signal, generates an ion count, and compares same with a plurality of SCC thresholds for classifying the sample in a quality category. A set of parameters characterizing the respective quality category, as well as the presence of mastitis in the animal, are finally displayed.

Abstract: In a system for evaluating a semiconductor device, a laser beam generating unit generates a laser beam, and an optical fiber receives the laser beam to heat an area of the semiconductor device. A current deviation detector or a voltage deviation detector is connected to a terminal of the semiconductor device. As a result, the current deviation detector or the voltage deviation detector detects a current deviation or a voltage deviation at the terminal of the semiconductor device.

Abstract: This invention relates to a fluid screening device, comprising: an impedance sensor including a cavity for holding a fluid to be screened, an impedance of the impedance sensor being affected by conditions of the fluid; an impedance measuring circuit for measuring the impedance of the impedance sensor with respect to at least one frequency; a processor for processing impedance data taken by the impedance measuring circuit for purposes of determining a condition of the fluid; and a connector which operatively couples the impedance sensor to the impedance measuring circuit, the connector allowing the impedance sensor to be selectively detached from the impedance measuring circuit.

Abstract: An apparatus and method for measuring electric current. The apparatus includes a conductive shunt for developing a voltage drop in response to current flow through the shunt, a temperature sensor for sensing the temperature of the shunt, and an amplifier for amplifying the voltage drop across the shunt. The voltage drop developed by the shunt has a known dependence upon the temperature of the shunt. The amplifier has an output for producing a current signal indicative of current flow through the shunt and has a gain dependent upon the temperature of the shunt, to compensate the current signal for changes in the voltage drop across the shunt due to the known dependence upon temperature of the voltage drop developed by the shunt.

Abstract: An interconnect is provided for making electrical connections with a semiconductor die. The interconnect includes a substrate having integrally formed contact members, configured to electrically contact corresponding contact locations on the die. The interconnect also includes a pattern of conductors formed separately from the substrate, and then bonded to the substrate, in electrical communication with the contact members. The conductors can be mounted to a multi layered tape similar to TAB tape, or alternately bonded directly to the substrate. In addition, each conductor can include an opening aligned with a corresponding contact member, and filled with a conductive material, such as a conductive adhesive or solder. The conductive material electrically connects the contact members and conductors, and provides an expansion joint to allow expansion of the conductors without stressing the contact members.

Abstract: A quasi-electrostatic sensing system surrounds an electrically conductive mass with an electric field, the magnitude of which is sensed at one or more locations to resolve a property of interest concerning the mass. The object intercepts a part of the electric field extending beween the AC-coupled "sending" electrode and the other "receiving" electrodes, the amount of the field intercepted depending on the size and orientation of the sensed mass, whether or not the mass provides a grounding path, and the geometry of the distributed electrodes. Because the response of the field to an object is a complex nonlinear function, adding electrodes can always distinguish among more cases. In other words, each electrode represents an independent weighting of the mass within the field; adding an electrode provides information regarding that mass that is not redundant to the information provided by the other electrodes.

Abstract: A method of determining the moisture content of material on a bobbin featuring a hollow core, the method comprising the steps of: (a) transmitting a plurality of microwaves substantially through a portion of the bobbin, such that the microwaves are transmitted microwaves; (b) receiving the transmitted microwaves such that the microwaves are received microwaves; (c) determining a phase shift and an attenuation from the received microwaves; (d) repeating steps (a) to (c) for at least a portion of the material on the bobbin, such that a plurality of phase shifts and a plurality of attentuations is obtained; (e) using at least one empirical factor selected from the group consisting of weight of the bobbin, temperature of the bobbin, shape of the bobbin and type of the material to correct the plurality of attenuations, producing a plurality of corrected attenuations; (f) calculating a raw moisture content of the material from the corrected attenuations; (g) correcting the plurality of phase shifts for an artefact

Abstract: An interconnect and system for testing semiconductor dice, and a test method using the interconnect are provided. The interconnect includes a substrate having patterns of contact members for electrically contacting the dice. The interconnect also includes patterns of conductors for providing electrical paths to the contact members. In addition, the interconnect includes contact receiving cavities configured to retain electrical connectors of a testing apparatus in electrical communication with the conductors. A die level test system includes the interconnect mounted to a temporary package for a singulated die. In the die level test system, the interconnect provides direct electrical access from testing circuitry to the die. A wafer level test system includes the interconnect mounted to a probe card fixture of a wafer probe handler. In the wafer level test system, the contact receiving cavities can be configured to support and align the interconnect to the probe card fixture.

Abstract: A method for determining the degree of hardening of a hardenable material determines the complex electrical permittivity. The .di-elect cons."(t=0)/.di-elect cons."(t) ratio, where .di-elect cons."(t) is the imaginary part of the complex electrical permittivity .di-elect cons.'(t)-j.di-elect cons."(t), is determined as a measure of the strength of the material at an instant in time t. The .di-elect cons.'max/.di-elect cons.'(t) ratio of the real part of the complex permittivity can also be determined as a measure of the strength. These ratios are similar in shape to the curve of the strengths of the hardenable material with time.

Abstract: An apparatus measures moisture content of cotton based upon rates of electrical charges flowing through the cotton. The apparatus includes a moisture sensor having first electrodes, second electrodes, and ground electrodes which are interdigitated between the first and second electrodes. The apparatus also includes a moisture content determination circuit that provides first electrical charges to the first electrodes, and second electrical charges to the second electrodes. The moisture content determination circuit determines the rate of electrical charge flowing from each of the first and second electrodes through the cotton to the ground electrodes, and determines the moisture content of the cotton based upon the rates of electrical charges flowing through the cotton. By thus applying first electrical charges to the first electrodes and second electrical charges to the second electrodes, the apparatus accurately measures the moisture content of the cotton over a wide range of moisture contents.

Abstract: A time domain reflectometry linear position sensing system having a transmission line with a helically wound inductor and a ground conductor. The transmission line includes a movable member that electrically connects with the ground member and which extends along the inductor from a first end a distance that depends on the position of an object whose position is being determined. A signal generator applies pulses between the first end and the ground conductor and a receiver receives reflections of those pulses. The delays between the applications of pulses and the receptions of reflections depend upon the position of the object. A position determining circuit determines the position of the object based upon the delays, beneficially by using sing-around. Beneficially, a third member extends a predetermined distance along the inductor from a second end. That third member provides a reference delay that can improve the system accuracy.

Abstract: A measurement method adjusts the IF bandwidth of a network analyzer to increase measurement speed for high dynamic range devices. According to the first preferred embodiment of the present invention, the bandwidth of the IF filter is adjusted for each corresponding measurement sweep of the network analyzer. The forward transmission and reflection characteristics of the device under test are measured using a first IF bandwidth, and the reverse transmission and reflection characteristics of the device are measured using a second IF bandwidth. When high measurement sensitivity of the forward transmission parameter of the high dynamic range device is sought, the first IF bandwidth is selected to be narrower than the second IF bandwidth. When high measurement sensitivity of the reverse transmission parameter of the high dynamic range device is sought, the first IF bandwidth is selected to be wider than the second IF bandwidth.