Type identification and parameter selection for drive control in a coriolis flowmeter
AssigneeMicro Motion, Inc.
InventorsRichard L. Smith, Brian T. Smith
Life of this patent
Estimating the term…
Abstract
A system for initializing parameters of a transmitter connected to a Coriolis flowmeter. This invention applies initial drive signals to a drive circuit which causes a flow tube to vibrate. The type of the flow tube is then determined from signals received from pick-off sensors associated with the flow tube. Parameters for generation of said drive signals are then set based upon the type of said flow tube.
Claims9
A method for operating a transmitter of a Coriolis flowmeter having at least one flow tube, a driver that oscillates said at least one flow tube, and sensors affixed to said at least one flow tube that produce pickoff signals representing motion of said at least one flow tube, said method comprising the steps of:
- applying initial drive signals to said driver which causes said flow tube to vibrate;
- determining a frequency of oscillation of said flow tube based on said pickoff signals;
- determining a type of said flow tube in response to said pickoff signals indicating said frequency of oscillation of said flow tube;
- and
- setting parameters for generation of said drive signal in response to a determination of said type of said flow tube.
A product used with a transmitter connected to a Coriolis flowmeter having at least one flow tube, a driver that oscillates said at least one flow tube, and sensors affixed to said at least one flow tube that produce pickoff signals representing motion of said at least one flow tube, said product comprising:
- a processor readable media for storing instructions;
- and
- instructions for directing a processor in said product to:
- generate initial drive signals for said driver to cause said flow tube to vibrate,
- apply said drive signals to said driver which causes said flow tube to vibrate,
- determine a frequency of oscillation of said flow tube based on said pickoff signals,
- determine a type of said flow tube in response to said pickoff signals indicating said frequency of oscillation of said flow tube, and
- set parameters for generation of said drive signal in response to a determination of said type of said flow tube.
An apparatus used with a transmitter connected to a Coriolis flowmeter having at least one flow tube, a driver that oscillates said at least one flow tube, and sensors affixed to said at least one flow tube that produce pickoff signals representing motion of said at least one flow tube, said apparatus comprising:
- means for applying initial drive signals to said driver which causes said flow tube to vibrate;
- means for determining a frequency of oscillation of said flow tube based on said pickoff signals;
- means for determining a type of said flow tube in response to said pickoff signals indicating said frequency of oscillation of said flow tube;
- and
- means for setting parameters for generation of said drive signal in response to a determination of said type of said flow tube.
The apparatus of claim 10 wherein said means of determining said type of said flow tube comprises:
- means for comparing said frequency of oscillation to a threshold frequency;
- and
- means for determining said type of said flow tube is a straight flow tube responsive to said frequency of oscillation being greater than said threshold frequency.
Dependencies are inferred from the claim text.