Parameter compensating system for a flowmeter

A fluid flowmeter compensating system, comprising a flowmeter providing a metered output in response to fluid flow, a transducer including a probe providing an output in response to a sensed parameter of the fluid, a converter connected to said transducer through means providing a connecting circuit and providing an output varying in response to the relative difference between the sensed parameter of the fluid and a preselected reference parameter for the fluid, said converter including means providing a source operatively connected to supply a constant signal to said probe provided by said transducer and to a reference impedance having a preselected magnitude corresponding to said preselected reference parameter and means responding to the signal variations at said reference impedance and said probe including amplifying means having a first input operatively connected to said reference impedance and a second input operatively connected to said probe through said connecting circuit means and providing a variation responsive signal continually tracking the change in the sensed parameter with respect to the reference parameter to said converter output, said converter output operatively connected to said amplifier output and to said probe through said connecting circuit means, and utilization means connected to said converter and to said flowmeter and providing a compensated metered output relating to said preselected reference parameter in response to said converter output.

A remote temperature sensing system for flowmeter compensation, comprising a flowmeter providing a metered output in response to fluid flow, a remotely located temperature-sensitive probe resistor having a variable resistance responding to changes in temperature of the sensed fluid and providing a preselected probe resistance at a reference temperature of said fluid, a converter connected to said remotely located temperature-sensitive resistor through a first conducting circuit having a first impedance magnitude at said reference temperature, said converter including a constant current source connected to said probe resistor through a reference resistor having a preselected reference resistance substantially equivalent to said preselected probe resistance and said first conducting circuit, said converter connected to said probe resistor through a second current conducting circuit having a second impedance magnitude at said reference temperature substantially equivalent to said first impedance magnitude, said converter including means connected to said reference resistor and to said remotely located probe resistor and providing an output signal representing the difference between the actual temperature of the fluid and the reference temperature in response to the sensed difference in resistance between said probe resistor and said reference resistor and continually cancelling erroneous signals due to impedance variations in said first and second circuits due to extraneous environmental surroundings, and utilization means connected to said converter and to said flowmeter and providing a compensated metered output relating to said reference temperature in response to said converter output signal.

A fluid flowmeter compensating system, comprising a flowmeter providing a metered output in response to fluid flow, a transducer including a probe resistance providing an output in response to a sensed parameter of the fluid, a signal converter remotely spaced from said transducer and including a source having an output circuit supplying a constant current signal connected in series electrical circuit including a reference resistor having a resistance equal to the probe resistance at a predetermined reference temperature and a first connecting circuit connected to said probe resistance, said signal converter including an operational amplifier with a substantially unity gain having a first high impedance input connected to said constant current output circuit and second high impedance input connected to said probe resistance through a second connecting circuit, said amplifier having an output connected to a first output circuit of said signal converter and said signal converter including a third connecting circuit having a resistance substantially equal to the resistance of said first connecting circuit and connecting said probe resistance to a second output circuit of said signal converter, said signal converter continually tracking the change in the probe resistance with respect to the reference resistance and providing an analog signal at said first and second output circuits indicative of the relative difference between the sensed temperature of the fluid and the predetermined reference temperature and continually cancelling erroneous signals due to resistance variations in said first and third connecting circuits, and utilization means operatively connected to said signal converter and to said flowmeter and providing a compensated metered output related to said preselected reference temperature in response to said analog signal.

A fluid flowmeter compensating system, comprising a flowmeter providing an output in response to fluid flow, a transducer including a probe providing an output in response to a sensed parameter of the fluid, a converter electrically connected to said transducer through a connecting circuit to said probe and providing an output signal indicative of the relative difference between the sensed parameter of the fluid and a preselected reference parameter, means operatively connected to said converter and to said flowmeter and providing a compensated metered output relating to said preselected reference parameter in response to said converter output signal, and means operatively connected to said converter and responding to said output signal and providing a first output during a normal sensing sequence and a second output different than said first output in response to an intermittent failure of a power source and indicating a sensed malfunction within the system and providing a malfunction warning, said converter including an amplifier operatively connected to said transducer and to said malfunction means and having an input circuit connected to said power source, said amplifier responding to the intermittent failure of said power source and saturating in response to the re-application of power and operatively transferring said malfunction means from said first output to said second output.

A fluid flowmeter compensating system, comprising a flowmeter providing a metered output in response to fluid flow, a transducer including a probe providing an output in response to a sensed parameter of the fluid, a converter connected to said transducer through means providing a connecting circuit and providing an output varying in response to the relative difference between the sensed parameter of the fluid and a preselected reference parameter for the fluid, said converter including means providing a source operatively connected to supply a constant signal to said probe provided by said transducer and to a reference impedance having a preselected magnitude corresponding to said preselected reference parameter and means responding to the signal variations in said reference impedance and said probe including amplifying means having a first input operatively connected to said reference impedance and a second input operatively connected to said probe through said connecting circuit means and providing a variation responsive signal continually tracking the change in the sensed parameter with respect to the reference parameter to said converter output, utilization means connected to said converter and to said flowmeter and providing a compensated metered output relating to said reference parameter in response to said converter and flowmeter outputs, and malfunction means operatively connected to said converter and providing a malfunction warning in response to a predetermined magnitude of said variation responsive signal to indicate any one of a plurality of possible sensed malfunctions including an open circuit within said connecting circuit, a short circuit within said connecting circuit, an excessive sensed fluid parameter, or an intermittent power failure.

A fluid flowmeter compensating system, comprising a flowmeter providing a metered output in response to fluid flow, a transducer including a probe impedance providing an output in response to a sensed parameter of the fluid, a signal converter connected to said transducer through means providing a connecting circuit and including means providing a constant signal source operatively connected to said transducer and to a reference impedance having a preselected magnitude corresponding to a preselected reference parameter for said fluid, said converter including amplifying means having a first input selectively connected to said reference impedance and a second input operatively connected to said remotely located probe through said connecting circuit means and an amplifier output responding to signal variations at said first and second inputs, said converter providing an output operatively connected to said amplifying means output and to said probe through said connecting circuit means and responsive to the relative difference between the sensed parameter of said fluid and the preselected reference parameter, and utilization means connected to said converter and to said flowmeter and providing a compensated metered output relating to said preselected reference parameter in response to said converter output, said converter including a simulated probe impedance selectively connected in circuit to calibrate said converter output in accordance with a simulated fluid parameter.

A fluid flowmeter compensating system, comprising a flowmeter providing a metered output in response to fluid flow, a transducer including a probe providing an output in response to a sensed parameter of the fluid, a signal converter providing an output responsive to the relative difference between the sensed parameter of the fluid and a preselected reference parameter for the fluid and connected to said transducer through means providing a connecting circuit and including amplifying means having a first input operatively connected to a reference impedance and a second input operatively connected to said probe through said connecting circuit means and an amplifier output responding to signal variations at said first and second inputs and connected to said signal converter output, utilization means operatively connected to said signal converter and to said flowmeter and providing a compensated metered output relating to said preselected reference parameter in response to said signal converter output, and an analog-to-digital converter responding to said signal converter output and providing a digital output including a readout display indicative of said signal converter output, said signal converter including a simulated probe impedance corresponding to a simulated preselected reference parameter of said fluid selectively connected operatively to said signal converter and said amplifying means including an off-set adjust circuit selectively variable with said simulated probe impedance connected in circuit until providing a predetermined calibrated output at said readout display indicative of the relative difference between the simulated parameter and the reference parameter.

A fluid flowmeter compensating system, comprising a flowmeter providing a metered output in response to fluid flow, a transducer including a probe providing an output in response to a sensed parameter of the fluid, a signal converter providing an output responsive to the relative difference between the sensed parameter of the fluid and a preselected reference parameter for the fluid and connected to said transducer through means providing a connecting circuit and including means providing a constant signal source operatively connected to said transducer and to a reference impedance, utilization means connected to said converter and to said flowmeter and providing a compensated metered output relating to said preselected reference parameter in response to said converter output, and an analog-to-digital converter responding to said signal converter output and providing a digital output including a readout display indicative of said signal converter output, said converter including a simulated probe impedance corresponding to a preselected reference parameter for said fluid selectively connected operatively to a constant signal output of said constant source and to said converter output, said constant source including means selectively operable and varying the constant signal at said source output with said simulated probe impedance connected in circuit until providing a predetermined calibrated output at said readout display indicative of the relative difference between the simulated parameter and the reference parameter.