Measurement apparatus with plural displays of measured parameter and selectable function thereof

• US 4,864,512 A
• Filed: 08/20/1986
• Issued: 09/05/1989
• Est. Priority Date: 08/20/1986
• Status: Expired due to Fees

• Current Assignee: John Fluke Mfg. Co., Inc. (Fortive Corp.)
• Original Assignee: John Fluke Mfg. Co., Inc. (Fortive Corp.)
• Inventors: Johnson, Tod K., Coulson, Kenneth A., Wong, Warren H.
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): Melnick, S. A.
• Application Number:
  US06/898,251
• Time in Patent Office: 1,112 Days
• Field of Search: 364/579, 364/570, 364/487, 364/481, 364/417, 364/550, 364/497-499, 364/483, 324/77 R, 324/121 R, 324/76 R, 324/114, 128/709, 128/710, 340/716, 340/815.21, 340/815.23
• US Class Current: 702/67
• CPC Class Codes: G01D 1/00 Measuring arrangements giving results other than momentary value of variable, of general application G01D3/00 takes precedence; in tariff metering apparatus G01D4/00; transducers not specially adapted for a specific variable G01D5/00
• CPC Class Codes: G01D 1/02 giving mean values, e.g. root means square values measuring root mean square values of currents or voltages G01R19/02
• CPC Class Codes: G01D 7/04 using a separate indicating element for each variable
• CPC Class Codes: G01R 15/125 for digital multimeters

Abstract

A measuring device includes a microprocessor controller programmed for performing any of a plurality of mathematical functions on a measured value of a parameter under test. The measuring device is provided with two displays, for displaying to a user both the parameter value and its mathematical function. Annunciators are provided to identify the displayed function of the parameter. Thus, together with the measured parameter value, offset, scaling, peak-to-peak values, or the uncertainty of a reading may be displayed, as well as statistical functions of the measurement, including an average, standard deviation, median or mode of the parameter under test. The methematical function display is updated concurrently with the display of the measured parameter value.

Claims

1. A measuring apparatus for controllably performing any of a plurality of mathematical functions on a value of a measured parameter under test and for simultaneously displaying the value of the measured parameter and the mathematical function thereof, comprising:

measuring means for measuring said parameter under test and for obtaining a value therefor;

programmable control means for controllably performing any of said plurality of mathematical functions on the value of said measured parameter; and

plural display means including at least first and second displays for concurrently displaying the value of said measured parameter and the mathematical function thereof performed by said programmable control means

further comprising function selecting means for selecting any one of said plurality of mathematical functions to be performed by said programmed control means.

2. A measuring apparatus as recited in claim 1 further comprising update means for updating said displayed mathematical function of said measured parameter.

3. A measuring apparatus as recited in claim 2 wherein said measuring means is operable for repeatedly reading values of said measured parameter for measurement and display, and

wherein said update means includes means for updating said displayed mathematical function of said measured parameter with each reading of said measured parameter, thereby providing for display updated values of said mathematical function of the measured parameter, said updated function values being current with the displayed value of said measured parameter.

4. A measuring apparatus as recited in claim 1 further comprising annunciating means for annunciating the mathematical function of said parameter under test performed by said programmable control means and displayed on at least one of said display means.

5. A measuring apparatus as recited in claim 1 further comprising uncertainty function selecting means for selecting a function identifying uncertainty in the parameter being measured to be performed by said programmable control means,

wherein said programmable control means comprises means for receiving an input from said uncertainty function selecting means, uncertainty parameter determining means responsive to the input and operable for determining the uncertainty in the parameter being measured, and means for providing to said second display an output signal indicative of the uncertainty of the value of the measured parameter displayed on said first display, whereby said plural display means concurrently display measurement results and the uncertainty of said measurement results.

6. A measuring apparatus as recited in claim 1 wherein said function selecting means comprises peak function selecting means for selecting a peak function to be performed by said programmable control means for identifying a peak value of the parameter being measured,

wherein said programmable control means comprises means for receiving an input from said peak function selecting means, peak value determining means for responding to the input by determining the peak value of the parameter being measured, and means for providing to said second display an output signal indicative of the peak value of the measured parameter displayed on said first display, whereby said plural display means concurrently display measurement results and a peak value of said measurement results.

7. A measuring apparatus as recited in claim 1 wherein said function selecting means comprises scaling selecting means for selecting a scaling function to be performed by said programmable control means for identifying a scaled value of the parameter being measured,

wherein said programmable control means comprises means for receiving an input from said scaling function selecting means, difference determining means responsive to the input and operable for determining a difference between the measured value of the parameter and a second value, means for dividing the difference by a third value selected by the user to provide a quotient representing a scaled form of the parameter being measured, and means for providing to said second display an output signal indicative of the scaled form of the measured parameter displayed on said first display, whereby said plural display means concurrently display measurement results and a scaled representation of said measurement results.

8. A measuring apparatus as recited in claim 1 wherein said function selecting means comprises offset function selecting means for selecting an offset function to be performed by said programmable control means for identifying an offset value of the parameter being measured,

wherein said programmable control means comprises means for receiving an input from said offset function selecting means, difference determining means responsive to the input and operable for determining a difference between the measured value of the parameter and a second value, to provide a difference representing an offset form of the parameter being measured, and means for providing to said second display an output signal indicative of the offset form of the measured parameter displayed on said first display, whereby said plural display means concurrently display measurement results and an offset representation of said measurement results.

9. A measuring apparatus as recited in claim 1 further comprising an input for a second parameter under test to permit display of values of both parameters and a mathematical function of values of said parameters, said measuring means being operable for measuring said second parameter and for obtaining a value thereof, said program control means operable for performing said mathematical function on the values of both of said measured parameters, and said plural display means operable for displaying both the values of said measured parameters and the mathematical function thereof.

10. A measuring apparatus as recited in claim 9 wherein said function selecting means comprises a ratio function selecting means for selecting a ratio function to be performed by said programmable control means for identifying a ratio of the parameters being measured,

wherein said programmable control means comprises means for receiving an input from said ratio function selecting means, ratio determining means responsive to the input and operable for determining the ratio of the parameters being measured, and means for providing to said second display an output signal indicative of the ratio of the measured parameters displayed on said first display, whereby said plural display means concurrently display measurement results and a ratio of said measurement result.

11. A measuring apparatus as recited in claim 1 wherein said parameter under test is an electrical parameter and further including a sensor means for sensing said electrical parameter,

wherein at least one of said first and second displays of said plural display means displays the value of the electrical parameter sensed by said sensor means.

12. A measuring apparatus for controllably performing any of a plurality of mathematical functions on a measured value of a parameter under test and for simultaneously displaying the measured value and the mathematical function thereof, comprising:

measuring means for measuring said parameter under test and for obtaining a value therefor;

programmable control means for controllably performing any of said plurality of mathematical functions on said measured parameter value;

plural display means including at least first and second displays for concurrently displaying said measured parameter value and a mathematical function thereof; and

annunciating means for annunciating the mathematical function of said parameter under test performed by said programmable control means and displayed on at least one of said display means;

wherein said annunciating means includes error indicating means for displaying error message associated with a mathematical function selected for performance by said programmable control means and for display on at least one of said display means.

13. A measuring apparatus for controllably performing any of a plurality of mathematical functioning on a measured value of a parameter under test and for simultaneously displaying the measured value and the mathematical function thereof, comprising:

measuring means for measuring said parameter under test and for obtaining a value therefor;

programmable control means for controllably performing any of said plurality of mathematical functions on said measured parameter values;

plural display means including at least first and second displays for concurrently displaying said measured parameter value and a mathematical function thereof; and

further comprising function selecting means for selecting a mathematical function to be performed,

wherein said programmable control means comprises a programmable microcomputer means, said microcomputer means programmed for receiving an input from said function selecting means and for responding to the input by performing the selected mathematical function and by providing to said second display an output signal indicative of the mathematical function of the measured parameter, whereby said plural display means concurrently display measurement results and mathematical functions of said measurement results.

14. A measuring apparatus for controllably performing any of a plurality of mathematical functions on a value of a measured parameter under test and for simultaneously displaying the value of the measured parameter and the mathematical function thereof, comprising:

measuring means for measuring said parameter under test and for obtaining a value therefor;

programmable control means for controllably performing any of said plurality of mathematical functions on the value of said measured parameter; and

plural display means including at least first and second displays for concurrently displaying the value of said measured parameter and the mathematical function thereof performed by said programmable control means,

further comprising statistical function selecting means for selecting from said plurality of mathematical functions a statistical function to be performed by said programmable control means for identifying a statistical characteristic of the parameter being measured,

wherein said programmable control means comprises means for receiving an input from said statistical function selecting means, statistical parameter determining means responsive to the input and operable for determining the selected statistical characteristic of the parameter being measured, and means for providing to said second display an output signal indicative of the statistical characteristic of the measured parameter displayed on said first display, whereby said plural display means concurrently display measurement results and a statistical characteristic of said measurement results.

15. A measuring apparatus as recited in claim 14, wherein said statistical function selecting means includes average selecting means for selecting an averaging function to be performed by said programmable control means and said statistical parameter determining means includes averaging means for determining an average value for measured values of the measured parameter.

16. A measuring apparatus as recited in claim 14, wherein said statistical function selecting means includes standard deviation selecting means for selecting a standard deviation function to be performed by said programmable control means and said statistical parameter determining means includes deviation means for determining a standard deviation for measured values of the measured parameter.

17. A measuring apparatus as recited in claim 14, wherein said statistical function selecting means includes median selecting means for selecting a median function to be determined by said programmable control means and said statistical parameter determining means includes median means for determining a median value for measured values of the measured parameter.

18. A measuring apparatus as recited in claim 14, wherein said statistical function selecting means includes mode selecting means for selecting a mode function to be determined by said programmable control means and said statistical parameter determining means includes mode means for determining a mode value for measured values of the measured parameter.

19. A measuring apparatus as recited in claim 14 wherein said statistical function selecting means is operable for selecting said structural function to be performed by said programmable control means from among a plurality of statistical functions.

20. A measuring apparatus for controllably performing any of a plurality of mathematical functions on a value of a measured parameter under test and for simultaneously displaying the value of the measured parameter and the mathematical function thereof, comprising:

measuring means for measuring said parameter under test and for obtaining a value therefor;

programmable control means for controllably performing any of said plurality of mathematical functions on the value of said measured parameter; and

plural display means including at least first and second displays for concurrently displaying the value of said measured parameter and the mathematical function thereof performed by said programmable control means,

further comprising memory means for storage of measurement values of the parameter being measured and access means for accessing measurement values stored in said memory means,

wherein said programmable control means comprises means for receiving an input from said access means, retrieval means responsive to the input and operable for accessing said memory means, and means for providing to said second display an output signal indicative of an accessed stored value of said parameter being measured, whereby said plural display means concurrently display a present measurement result and a representation of previously measured values of said parameter under test.

21. A measuring apparatus as recited in claim 20, wherein said access means comprises means for identifying a storage location in said memory means to be accessed by said retrieval means, and wherein said retrieval means includes means for accessing the memory location identified by said means for identifying.

22. A measuring apparatus as recited in claim 21, wherein said second display comprises annunciating means for identifying said memory location accessed by said programmable control means.

23. A measuring apparatus as recited in claim 20 wherein said access means comprises burst means for accessing said memory means in a burst mode, and said programmable control means includes means responsive to said burst means by sequentially accessing data stored in a plurality of locations of said memory means, said means for providing further including means responsive to said burst means for providing to said second display a sequence of output signals indicative of said sequentially accessed data from said plurality of locations of said memory means, whereby said plural display means concurrently displays a present measurement result and a representation of a sequence of previously measured values of said parameter under test.

24. The system of claim 23 wherein said programmable control means is operable for performing said mathematical function on each of said sequentially accessed data from said plurality of locations of said memory means thereby to display a sequence of values of the measured parameter and a corresponding sequence o values respectively obtained by performing the selected mathematical function thereon.

25. In a measuring system having an input for a measured parameter, a measuring circuit for providing a digital signal representative of the measured parameter, a microcomputer for converting the digital signal representative of the measured parameter to a display signal, a user controlled switching means for controlling the measuring circuit to output a signal representative of a desired particular parameter and a display means for displaying a value of the desired particular parameter as measured by the measuring circuit, the improvement comprising:

selecting means in said user controlled switching means for selecting a desired mathematical function to be performed on the measured parameter,

processing means responsive to said selecting means of said user controlled switching means for performing a selected mathematical function on the value of the measured parameter in accordance with a setting of said selecting means,

said processing means outputting second display signals representative of a result of performing said selected mathematical function on the value of the measured parameter, and

second display means for displaying a value represented by said second display signals, thereby displaying said mathematical function of said value of the measured parameter on said second display means while said value of the measured parameter is displayed on said first mentioned display means.

26. The system claim 25 wherein said measuring circuit, said microcomputer, said switching means, said display means, said selecting means, said processing means and said second display means are arranged to form a single digital multimeter for measuring electrical parameters.

27. The system of claim 26 wherein said processing means comprises means for computing an uncertainty of said measured parameter.

28. The system of claim 27 wherein said means for computing an uncertainty comprises means operably for computing an equation A*X+B, wherein X is the value of the measured parameter expressed in a particular dimensional unit, A is a coefficient representing a percentage of uncertainty of X, and B is a quantity having a dimensional unit corresponding to the dimensional unit of the measured parameter.