Magnetic flowmeter having automatic ranging
AssigneeEmerson Electric Co.
InventorsWilliam R. Freund, Jr., John C. Grebe, Jr.
Life of this patent
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Abstract
The internal accuracy of a magnetic flowmeter signal processing chain is preserved throughout an extended flow range by means of an automatic ranging system which automatically multiplies the gain of an amplifier in the chain as the flow rate decreases, and simultaneously divides its output to produce an essentially continuous output signal. The automatic ranging system eliminates manual range setting and is not observable from outside the system in the steady state.
Claims10
In a magnetic flowmeter comprising a body adapted to be connected in a flow system for measuring the flow of a fluid therethrough, means for generating a magnetic field in said fluid flowing through said body, means for producing a flow-dependent signal dependent on the electric field generated in said fluid flowing through said magnetic field, and amplifier means for amplifying said flow-dependent signal to produce an amplified flow-dependent signal, and further signal processing means for receiving said amplified flow-dependent signal and producing an output signal dependent thereon,
- the improvement comprising automatic ranging means comprising first means for increasing the gain of said amplifier means as said flow-dependent signal decreases and second means for producing a signal in said further signal processing means indicative of said increase in gain.
Dependencies are inferred from the claim text.