Product Data Sheet PS-001316, Rev. B April 2013 Micro Motion® Model 7950 and Model 7951 Signal Converters Micro Motion® Model 7950 and Model 7951 signal converters are the perfect complement to Micro Motion gas and liquid density and viscosity meters. These devices convert the meter output signals into accurate process measurements. Because they are easy to use, you can quickly set up and configure the signal converters to meet your individual process needs. Receives inputs from Micro Motion gas density, specific gravity, liquid density, and liquid viscosity meters Provides high accuracy readings of density, specific gravity, viscosity, and process variables Outputs readings in multiple formats such as kg/m3, g/cm3, °API, °Brix, and % concentration Easy-to-use, four-line, backlit configurable display Wide-ranging I/O capabilities, with the option to increase the quantity of inputs/outputs available Supports wide application range, including interface detection, fuel density, and quality control Wall-mount signal converter Panel-mount signal converter
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1. A device for use in measuring the root mean square value of an input signal, comprising first and second substantially identical heating elements, means for applying to the first heating element a signal representative of the input signal, means for sensing a temperature differential between the first and second heating elements and for providing a signal representative thereof, a feedback circuit connected to receive the signal representative of temperature differential and to apply a feedback signal to the second heating element so as to reduce the said temperature differential, a source of reference signal, and an adjustable A.C. power source responsive to the reference signal and a signal from the feedback circuit to deliver to each of the first and second heating elements an amount of power dependent of the difference between the reference signal and said signal from the feedback circuit, said power source being arranged to deliver substantially the same amount of power to each of the said heating elements, whereby the total power received by each heating element remains substantially constant and the feedback signal is representative of the RMS value of the input signal.
2. A device according to claim 1, wherein the means for sensing temperature differential between the first and second heating elements comprises respective first and second substantially identical thermocouples in thermal contact with the respective first and second heating elements.
3. A circuit according to claim 1, wherein the feedback circuit comprises an amplifier connected to receive and amplify said signal representative of temperature differential and a function generator circuit arranged to receive the amplified signal and to produce an output, the amplitude whereof is linearly related to the square root of the amplitude of the said amplified signal, said output constituting said feedback signal.
4. A device according to claim 1, wherein the adjustable A.C. power source comprises a modulator connected to receive at least one DC signal and providing an output representative thereof which is alternating current.
5. A device for use in measuring the root mean square value of an input signal comprising first and second substantially identical heating elements, means for applying to the first heating element a signal representative of the input signal, means for sensing a temperature differential between the first and second heating elements and for providing a signal representative thereof, a feedback circuit connected to receive the signal representative of temperature differential and to apply a feedback signal having an amplitude proportional to the square root of the amplitude of the signal representative of temperature differential to the second heating element so as to reduce the said temperature differential, a source of reference signal, a level control circuit having an input and an output and receiving at its input the signal representative of temperature differential and the reference signal and producing at its output a control signal representative of the square root of the difference between the signals at its input, an adjustable A.C. power source connected to receive the control signal and connected to the first and second heating elements respectively for delivering substantially the same power to each of the said heating elements, said source being adapted to adjust the power in response to the control signal so that the total power received by the second heating element from the feedback signal and from the power source remains substantially constant, whereby a signal from the feedback circuit representative of the feedback signal applied to the second heating element to reduce the temperature differential serves as an output representative of the RMS value of the input signal.
6. A device according to claim 3, comprising means for applying said amplified signal to said power source as said signal from the feedback circuit.
1. A device for use in measuring the root mean square value of an input signal, comprising first and second substantially identical heating elements, means for applying to the first heating element a signal representative of the input signal, means for sensing a temperature differential between the first and second heating elements and for providing a signal representative thereof, a feedback circuit connected to receive the signal representative of temperature differential and to apply a feedback signal to the second heating element so as to reduce the said temperature differential, a source of reference signal, and an adjustable A.C. power source responsive to the reference signal and a signal from the feedback circuit to deliver to each of the first and second heating elements an amount of power dependent of the difference between the reference signal and said signal from the feedback circuit, said power source being arranged to deliver substantially the same amount of power to each of the said heating elements, whereby the total power received by each heating element remains substantially constant and the feedback signal is representative of the RMS value of the input signal.
2. A device according to claim 1, wherein the means for sensing temperature differential between the first and second heating elements comprises respective first and second substantially identical thermocouples in thermal contact with the respective first and second heating elements.
3. A circuit according to claim 1, wherein the feedback circuit comprises an amplifier connected to receive and amplify said signal representative of temperature differential and a function generator circuit arranged to receive the amplified signal and to produce an output, the amplitude whereof is linearly related to the square root of the amplitude of the said amplified signal, said output constituting said feedback signal.
4. A device according to claim 1, wherein the adjustable A.C. power source comprises a modulator connected to receive at least one DC signal and providing an output representative thereof which is alternating current.
5. A device for use in measuring the root mean square value of an input signal comprising first and second substantially identical heating elements, means for applying to the first heating element a signal representative of the input signal, means for sensing a temperature differential between the first and second heating elements and for providing a signal representative thereof, a feedback circuit connected to receive the signal representative of temperature differential and to apply a feedback signal having an amplitude proportional to the square root of the amplitude of the signal representative of temperature differential to the second heating element so as to reduce the said temperature differential, a source of reference signal, a level control circuit having an input and an output and receiving at its input the signal representative of temperature differential and the reference signal and producing at its output a control signal representative of the square root of the difference between the signals at its input, an adjustable A.C. power source connected to receive the control signal and connected to the first and second heating elements respectively for delivering substantially the same power to each of the said heating elements, said source being adapted to adjust the power in response to the control signal so that the total power received by the second heating element from the feedback signal and from the power source remains substantially constant, whereby a signal from the feedback circuit representative of the feedback signal applied to the second heating element to reduce the temperature differential serves as an output representative of the RMS value of the input signal.
6. A device according to claim 3, comprising means for applying said amplified signal to said power source as said signal from the feedback circuit.
795X Series Flow computers for the gas industry 795X Series flow computers for the gas industry Specification sheet b1248 Jan 2006 Flow computers. Solartron 7950, 7951 and 7955 flow computers acquire primary data directly from flowmeters, density and temperature sensors, pressure. Solartron software library The Solartron application library.