Apparatus and method for calibrating a measuring device

• US 5,012,667 A
• Filed: 02/22/1990
• Issued: 05/07/1991
• Est. Priority Date: 03/18/1988
• Status: Expired due to Fees

• Current Assignee: Great Plains Industries Incorporated (Great Plains Ventures, Inc.)
• Original Assignee: Great Plains Industries Incorporated (Great Plains Ventures, Inc.)
• Inventors: Kruse, Richard M.
• Primary Examiner(s): Noland, Tom
• Application Number:
  US07/484,044
• Time in Patent Office: 439 Days
• Field of Search: 73/1 R, 73/3, 364/571.01, 364/571.02, 364/571.03, 364/571.04, 364/571.05, 364/571.06, 364/571.07, 364/571.08
• US Class Current: 73/1.34
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

A calibration apparatus includes a microcomputer-based calibrator unit, functioning separately from a measuring device to be calibrated, and a coupling coil, through which calibration information generated by the calibrator unit is electromagnetically transmitted to the measuring device to which the coil is strapped or otherwise connected. This permits the measuring device to be calibrated without the measuring device being removed from the environment in which it is to make measurements. The methodology of the apparatus permits the measuring device to be calibrated either with standard calibration data, such as whereby the measuring device is calibrated to a factory standard calibration, or with variable calibration data, such as whereby a then-current calibration of the measuring device is "tweaked".

Claims

1. An apparatus for calibrating a measuring device, said apparatus comprising:

calibration signal generating means for generating, independently of the operation of the measuring device, a calibration signal, the calibration signal generating means comprising;

power supply means for providing electrical energy to said apparatus;

switch for activating said power supply means; and

timer means, having a time period which expires if the time period is not restarted prior thereto, for automatically deactivating said power supply means when said time period expires; and

communicating means for communicating said calibration signal to the measuring device without disassembling the measuring device.

2. An apparatus as defined in claim 1, wherein:

said calibration signal generating means includes;

a microcomputer, including data storage means for storing predetermined calibration data; and

data entry means for inputting new calibration data into said microcomputer and for instructing said microcomputer whether to use predetermined calibration data or new calibration data; and

said microcomputer further includes means for computing and outputting said calibration signal in response to predetermined calibration data or new calibration data as instructed in response to said data entry means.

3. An apparatus as defined in claim 2, wherein said calibration signal generating means further includes a portable housing in which said microcomputer and said data entry means are disposed.

4. An apparatus as defined in claim 2, wherein:

said calibration signal generating means further includes a visual output display connected to said microcomputer; and

said microcomputer further includes means for outputting text visually through said visual output display to prompt an operator of said apparatus to operate said data entry means.

5. An apparatus as defined in claim 1, wherein said communicating means includes electromagnetic means for transmitting said calibration signal electromagnetically from said calibration signal generating means to the measuring device.

6. An apparatus as defined in claim 1, wherein:

said calibration signal generating means includes;

a microcomputer;

a keypad connected to said microcomputer;

a display connected to said microcomputer; and

connector means for connecting said microcomputer to said communicating means; and

said communicating means includes an electrical current conductive coil adapted for connecting to siad connector means.

7. An apparatus as defined in claim 6, wherein said calibration signal generating means further includes a portable housing, separate from the measuring from the measuring device, having said microcomputer, said keypad, said display and said connector means mounted therein.

8. An apparatus as defined in claim 1, wherein said calibration signal generating means includes:

a display

a function switch disposed adjavent said display; and

means for outputting through said display adjacent said function switch one of a plurality of indicia designating a specific one of a plurality of functions to be selected upon actuation of said function switch.

9. An apparatus for calibrating a measuring device which is designed to have a preset calobration and which displays a measurement of a measured parameter in response to an existing calibration of the measuring device, said apparatus comprising:

preset calibration means for generating a calibration signal to calibrate the measuring device to the preset calibration thereof;

variable calibration means for genreating a calibration signal to calibrate the measuring device to a calibration both in response to a measurement by the measuring device displayed in response to the existing calibration and a magnitude of the measured parameter and in response to a measurement desired to be displayed by the measuring device in response to the same magnitude of the measured parameter;

means for operating a selected one of said preset calibration means and said variable calibration means;

means for communicating to the measuring device the calibration signal of the selected one of said preset calibration means and said variable calibration means;

wherein said preset calibration means includes;

memory means for storing data, said memory means having predetermined calibration data stored therein; and

first computing means, responsive to said means for operating and said predetermined calibration data, for computing the calibration signal of said preset calibration means; and

wherein said variable calibration means includes;

data entry means for entering into said variable calibration means responsive calibration data determined from the displayed measurement of the measuring device and the desires measurement; and

second computing means, responsive to said means for operating and said responsive calibration data, for computing the calibration signal of said variable calibration means,

10. An apparatus as defined in claim 9, further comprising a housing, separate from the measuring device, having said preset calibration means, said variable calibration means and said means for operating disposed therein.

11. An apparatus as defined in claim 10, wherein said means for communicating includes:

a coil; and

electrical conductor means, adapted for extending from said housing, for connecting said coil to said preset calibration means and said variable calibration means.

12. An apparatus as defined in claim 9, wherein said means for communicating includes:

an electrical coil adapted to be connected to the measuring device; and

conductor means connecting said coil to said preset calibration means and said variable calibration means.

13. A method of calibrating a measuring device, said method comprising the steps of:

generating, separately from the measuring device, a calibration signal, said generating a calibration step including;

selecting a standard calibration mode or a variable calibration mode;

in response to selecting a standard calibration mode, generating a calibration count from preset calibration data;

in response to selecting a variable calibration mode, entering variable calibration mode calibration data and generating a calibration count from the entered variable calibration mode calibration data; and

in response to selecting a variable calibration mode, determining whether the measuring device is adapted to receive one calibration count or two calibration counts;

converting the calibration signal into electromagnetic energy; and

coupling the electromagnetic energy to the measuring device.

14. A method as defined in claim 13, wherein said step of determining whether the measuring device is adapted to receive one calibration count or two calibration counts includes:

generating a first set of a predetermined number of pulses and transmitting the pulses of the first set to the measuring device at a first frequency;

detecting a first reading output from the measuring device in response to the pulses transmitted at the first frequency;

generating a second set of the predetermined number of pulses and transmitting the pulses of the second set to the measuring device at a second frequency;

detecting a secon reading putput from the measuring device in response to the pulses transmitted at the second frequency;

comparing the first reading with the second reading to determine if the readings are equal;

designating the measuring device for one calibration count if the readings are equal; and

designating the measuring device for two calibration counts if the readings are not equal.