Abstract: There is disclosed a radar transmitter for emulsion measurement comprising a probe defining a transmission line for sensing impedance. A first excitation circuit is connected to a top of the probe for generating downward travelling excitation signals on the transmission line and receiving a reflected signal from the transmission line. A second excitation circuit is connected to a bottom of the probe for generating upward travelling excitation signals on the transmission line and receiving a reflected signal from the transmission line, each of the reflected signals comprising a waveform of probe impedance over time. A controller is operatively connected to the excitation circuits.

Abstract: A radar transmitter for emulsion measurement comprises a probe defining a transmission line for sensing impedance. A pulse circuit is connected to the probe for generating pulses on the transmission line and receiving a reflected signal from the transmission line. The reflected signal comprises a waveform of probe impedance over time. A controller is operatively connected to the pulse circuit. The controller profiles content of the emulsion responsive to the waveform by transforming the waveform into impedance relative to distance, converting the transformed waveform into effective dielectric relative to distance, determining mixture content of the emulsion at select distances responsive to the effective dielectric at the select distances and developing an output representing mixture content relative to level units.

Abstract: There is disclosed herein a method of measuring and profiling a process liquid in a process vessel. The process liquid includes an emulsion layer between two media of differing dielectric constants. An electromagnetic signal is generated and transmitted along a probe, defining a transmission line, extending into the vessel. The transmission line comprises a conductor in contact with the process liquid with an insulating coating on the conductor to maximize signal penetration in the process liquid. A reflected signal is received from the transmission line and a programmed controller is operatively connected to the probe for measuring characteristics of reflected signal energy along the transmission line for profiling the emulsion layer.

Abstract: A guided wave radar level measurement instrument comprises a probe defining a transmission line for sensing material level. A pulse circuit is connected to the probe for generating pulses on the transmission line and receiving reflected signals from the transmission line. The pulse circuit comprises a pulse generator for generating a transmit pulse, a bridge circuit having a diode switched front end connected between the pulse generator and a differential circuit. The transmission line is connected to one side of the differential circuit. Generated pulses from the pulse generator are supplied to both sides of the differential circuit and reflected signals from the transmission line are supplied to one side of the differential circuit.

Abstract: There is disclosed herein a method of measuring and profiling a process liquid in a process vessel. The process liquid includes an emulsion layer between two media of differing dielectric constants. An electromagnetic signal is generated and transmitted along a probe, defining a transmission line, extending into the vessel. The transmission line comprises a conductor in contact with the process liquid with an insulating coating on the conductor to maximize signal penetration in the process liquid. A reflected signal is received from the transmission line and a programmed controller is operatively connected to the probe for measuring characteristics of reflected signal energy along the transmission line for profiling the emulsion layer.

Abstract: A guided wave radar level measurement instrument comprises a probe defining a transmission line for sensing material level. A pulse circuit is connected to the probe for generating pulses on the transmission line and receiving reflected signals from the transmission line. The pulse circuit comprises a pulse generator for generating a transmit pulse, a bridge circuit having a diode switched front end connected between the pulse generator and a differential circuit. The transmission line is connected to one side of the differential circuit. Generated pulses from the pulse generator are supplied to both sides of the differential circuit and reflected signals from the transmission line are supplied to one side of the differential circuit.

Abstract: A radar transmitter for emulsion measurement comprises a probe defining a transmission line for sensing impedance. A pulse circuit is connected to the probe for generating pulses on the transmission line and receiving a reflected signal from the transmission line. The reflected signal comprises a waveform of probe impedance over time. A controller is operatively connected to the pulse circuit. The controller profiles content of the emulsion responsive to the waveform by transforming the waveform into impedance relative to distance, converting the transformed waveform into effective dielectric relative to distance, determining mixture content of the emulsion at select distances responsive to the effective dielectric at the select distances and developing an output representing mixture content relative to level units.

Abstract: A through air level measurement instrument for use in minimizing tank rattle comprises a housing and an antenna secured to the housing. A process adaptor is associated with the antenna and the housing for securing the instrument to a closed tank with the antenna directed into an interior of the closed tank. A control in the housing generates and receives a high frequency signal using an electromagnetic radiating element proximate the antenna. The control comprises an equivalent time sampling circuit including a main oscillator driving a timing circuit controlling timing between transmitted and sample pulses. A noise generator is operatively associated with the main oscillator to randomly modulate timing of the main oscillator. The control minimizes inaccuracies caused by tank rattle.

Abstract: A through air level measurement instrument for use in minimizing tank rattle comprises a housing and an antenna secured to the housing. A process adaptor is associated with the antenna and the housing for securing the instrument to a closed tank with the antenna directed into an interior of the closed tank. A control in the housing generates and receives a high frequency signal using an electromagnetic radiating element proximate the antenna. The control comprises an equivalent time sampling circuit including a main oscillator driving a timing circuit controlling timing between transmitted and sample pulses. A noise generator is operatively associated with the main oscillator to randomly modulate timing of the main oscillator. The control minimizes inaccuracies caused by tank rattle.

Abstract: A loop powered process instrument comprises a control circuit measuring a process variable and developing a control signal representing the process variable. An output circuit for connection to a two-wire process loop controls current on the loop in accordance with the control signal. A power supply circuit is connected to the output circuit and the control circuit for receiving power from the two-wire process loop and supplying power to the control circuit. The power supply comprises cascaded charge pump circuits.

Abstract: A process control instrument includes a circuit board having a control circuit for generating or receiving a high frequency signal. An antenna includes an electrical conductor. An intrinsic safety circuit couples the control circuit to the antenna and comprises a microstrip transmission line on the circuit board electrically connecting the control circuit to the electrical conductor. A safety stub has a first end electrically connected to the transmission line proximate the electrical conductor and a second end connected to a ground of the control circuit.

Abstract: A process control instrument includes a circuit board having a control circuit for generating or receiving a high frequency signal. An antenna includes an electrical conductor. An intrinsic safety circuit couples the control circuit to the antenna and comprises a microstrip transmission line on the circuit board electrically connecting the control circuit to the electrical conductor. A safety stub has a first end electrically connected to the transmission line proximate the electrical conductor and a second end connected to a ground of the control circuit.

Abstract: A process control instrument includes a circuit board having a control circuit for generating or receiving a high frequency signal. An antenna includes an electrical conductor. An intrinsic safety circuit couples the control circuit to the antenna and comprises a microstrip transmission line on the circuit board electrically connecting the control circuit to the electrical conductor. A safety stub has a first end electrically connected to the transmission line proximate the electrical conductor and a second end connected to a ground of the control circuit.

Abstract: A loop powered process instrument comprises a control circuit measuring a process variable and developing a control signal representing the process variable. An output circuit for connection to a two-wire process loop controls current on the loop in accordance with the control signal. A power supply circuit is connected to the output circuit and the control circuit for receiving power from the two-wire process loop and supplying power to the control circuit. The power supply comprises cascaded charge pump circuits.

Abstract: A sheet feeding apparatus (10) and method are disclosed that are fast, efficient, easy to set up and involve a minimum number of components. The sheet feeding mechanism (10) includes a first gripping member (20) comprised of two first suction cups (21) and a second gripping member (40) comprised of two second suction cups (41). The first suction cups (21) are moved along a first path (P1) between a first position and a second position by a first guide means (25). The second suction cups (41) are moved along a second path (P2) between a third position and a fourth position by a second guide means (60). Vacuum means (22,42) are connected to the suction cups (21,41) for picking up, holding and releasing sheets (TS). The first suction cups (21) pick up a sheet (TS) and transfer it to the second suction cups (41) which take the sheet (TS) to a lamination unit (LU1,LU2).

Abstract: Apparatus for cutting the leading and trailing edges of an opaque sheet angling initially at an offset angle with respect to a cutting blade includes a pair of light sources and a pair of light sensors opposite said light sources. An opaque sheet to be cut is moved at right angles to a line extending between said pairs of light source and sensors to bring said article edges to and past said pairs of light sources and sensors. The sensors produce article edge angle indicating signals which indicate the time difference each edge reaches said pair of sensors. Means are provided responsive to said signals which adjust the blade angle to be parallel to each article edge so the blade cuts parallel to each edge. The angle indicating could be signals which are a direct measure of the difference in times each edge reaches the sensors.

Abstract: A color monitor includes R G and B gain blocks, in the form of balanced multipliers, and a potentiometer picture control for supplying a common DC gain control voltage to the differentially coupled transistor pairs in the gain blocks. A common black level control adjusts the zero level for the signals. Changes in gain control voltage do not affect black level or color balance of the picture tube display.

Abstract: A television signal receiving apparatus having a first input for receiving a composite video signal and a second input for receiving a direct-drive RGB signal includes an electronic switching circuit for automatically switching between composite video and RGB modes of operation. The switching circuit is responsive to the presence of the sync component of an RGB signal at the second input for automatically establishing the RGB mode of operation wherein only the input RGB signal is used to form the image display and is responsive to the absence of the sync component of the RGB signal at the second input for establishing the composite video mode of operation wherein the composite video signal at the first input is used to form the image display. Provisions are included for developing an override signal for allowing the development of a mixed mode image display.

Abstract: An integratable amplifier is disclosed for developing a high level output signal with reduced power dissipation. The amplifier includes a first circuit (108, 110) which responds to an input signal for developing first and second signal currents whose amplitudes increase and decrease, respectively, in response to an input signal transition of a given direction. A second circuit (32a) receives the first signal current for establishing a third signal current which mirrors the first signal current. The second and third signal currents are received by a third circuit (70a) for conversion thereof to an amplified output signal. To stabilize the gain of the amplifier, a negative feedback path (50a) is coupled between the input signal and the output signal.

Abstract: A stabilization network is disclosed which compensates for variable emission characteristics of a cathode in a television receiver's cathode ray tube. During the receiver's vertical interval, a variable gain video amplifier applies a black level D.C. voltage to the cathode. The resulting cathode current is sensed and compared to a low level reference current. If the cathode current does not equal the reference current, a control signal is applied to the amplifier. The amplifier responds to changing its D.C. output voltage until the cathode current is equal to the reference current. The amplifier also responds to the control signal by altering its gain so that, when a video signal is received, the cathode develops peak white currents of a given value in response to peak white portions of the video signal.