JPH0291535A - Measuring instrument for differential pressure - Google Patents

Abstract

PURPOSE:To measure for an entire range capable of measuring with high accuracy by measuring any one of the segments selectively, which are divided into the desired number of segments in such a manner that the entire range capable of measuring is covered with every section while deviating slightly so as to be partly superposed with each other. CONSTITUTION:The measurement range capable of measuring is segmented to the desired number (4 pieces) of segments so that the entire range can be covered by span widths expanded by desired widths, longer than the measurable span widths shown as the rated range, while deviating slightly so as to be partly superposed with each other. Then, adequate correction curves are decided at every segment and stored in storage means 1, and adequate one of the segments is selected with selecting means 2 in the manner of inputting lower and upper limits values of the span width for the measuring value to be measured through range set means 21. Further, the correction curve corresponding to the segment selected by arithmetic means 3 is called from the storage means 1, then a detected value Pin prior to the correction is corrected in accordance with the called correction curve and a measuring signal is outputted Pout. The measurement for the entire range capable of measuring is thereby performed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a differential pressure measuring device that can correct more accurately by improving the correction means of the differential pressure measuring device.

<Prior Art> FIG. 4 is an explanatory diagram of correction of a conventional differential pressure measuring device that has been commonly used.

In the figure, the vertical axis shows the error and the horizontal axis shows the input6.
Point A indicates the minus maximum Subang value, and point B indicates the plus maximum Subang value.

The error characteristics of the output with respect to the input are calculated from measurement data at several points, an approximate curve y = f (x) that approximates the characteristics of the output error is calculated, and the error with respect to the input is corrected using this curve. be.

<Problems to be Solved by the Invention> However, the differential pressure measuring device is used by arbitrarily setting a measurement range of 10 to 100 times according to various objects to be measured.

Therefore, with the conventional approximate curve Y=f (x) for plus and minus full spans, it is difficult to perform corrections that provide high precision for various measurement ranges.

In other words, if the correction curve is set to perform good correction in a narrow range, the correction will not be sufficient in the case of a wide range, and conversely, if the correction curve is set to perform good correction in a wide range, the compensation will not be sufficient in the case of a narrow range. Correction cannot be made sufficiently.

Therefore, if the measurement accuracy is made stricter, the measurable range width becomes narrower. In order to widen the measurable range, the measurement accuracy must be reduced.

The present invention solves this problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a differential pressure measuring device that can correct more accurately by improving the correction means of the differential pressure measuring device.

Means for Solving the Problems> In order to achieve this object, the present invention provides a differential pressure measuring device that corrects a detected value based on a correction curve corresponding to the characteristics of the device and outputs it as a measurement signal. Each section is divided into sections on the required side so that the required width is wider than the indicated measurable span width so that the entire measurable range can be covered, and each section is slightly shifted so that each section partially overlaps. A storage means for determining an appropriate correction curve for each case and storing the correction curve, and a range setting means for inputting the lower and upper limits of the subband width of the measured value, thereby selecting an appropriate one of the above-mentioned categories. and a calculation means for reading a correction curve corresponding to the selected category from the storage means, correcting the detected value based on the called correction curve, and outputting a measurement signal. This is a configuration of a characteristic differential pressure measuring device.

Effect〉 In the above configuration, first, (1) Obtain characteristic data of the output of the device with respect to the input.

(2) Divide the required width so that it can cover the entire measurable range with a width wider than the measurable width shown as the rating, and shift it slightly so that each part overlaps. Classified into

(3) Determine an appropriate correction curve for each section and store the correction curve in the storage means.

(4) One of the appropriate categories is selected by the selection means by inputting the lower and upper limits of the subband width of the measurement value to be measured through the range setting means.

(5) The calculation means retrieves from the storage means a correction curve corresponding to the category selected by the selection means, and the detected value is corrected based on the retrieved correction curve, and a measurement signal is output.

<Embodiment> FIG. 1 is a block diagram illustrating a main part of an embodiment of the present invention.

In the figure, 1 is designed to cover the entire measurable range with a width that is wider than the measurable width shown as the rating, and each partially overlaps, as shown in Figure 2. The storage means divides the data into desired sections by shifting it by 1, determines an appropriate correction curve for each section, and stores the correction curve.

In this case, the measurable width indicated as the rating is 500mmHg, and the required widened width is 600mm.
Hg, measurable range is +500mmHg to -5
00mmHg and is divided into four sections. That is, A
, B, C, and D modes.

Reference numeral 2 denotes a selection means for selecting an appropriate one of the categories by inputting the lower limit and upper limit of the subband width of the measured value via the range setting means 21.

In this case, the lower limit and upper limit are OmmHg, +5
00 mmHg is used.

Reference numeral 3 denotes an arithmetic means for reading a correction curve corresponding to the selected section from the storage means 1, correcting the detected value based on the called correction curve, and outputting a measurement signal.

In the above configuration, first, (1) obtain characteristic data of the output of this differential pressure measuring device with respect to the input;

(2) Measurable span width indicated as rating (50
Subang width (600mmH), which is wider than the required width (0mmHg)
g) The measurable range (from +500 mmHg to -500 mmHg) is divided into the required number (4) by shifting the temperature so that they can cover the entire range and partially overlap each other.

(3) Determine an appropriate correction curve for each section and store the correction curve in the storage means 2.

(4) Lower limit of the width of the measured value [(Omm H
g) and the upper limit value (+500 mmHg) are inputted via the range setting means 21, one of the appropriate categories is selected by the selection means 3.

(5) The calculation means 4 retrieves from the storage means 2 the correction curve corresponding to the category selected by the selection means 3, and the detected value PjTL before correction is corrected based on the retrieved correction curve, and the measurement signal is output Po■ t will be done.

As a result, (1) Since the subband of each category is narrower than the subband that covers the entire measurable range, it is possible to improve the correction accuracy relatively easily.

(2) Each category is divided into the required number of categories so that they can cover the entire measurable range range, and are shifted slightly so that each category partially overlaps, so it is difficult to select one of the categories. Since the entire measurable range can be covered, the entire measurable range can be measured with high accuracy.

In the above-described embodiment, the number of divisions is four. However, the number of divisions is not limited to this, and for example, there may be five divisions. You can divide it.

Furthermore, if it is desired to particularly improve the accuracy in a specific range, it is of course possible to separately provide a narrower span width for that section, as shown in E mode in FIG. 3.

<Effects of the Invention> As explained above, the present invention provides a differential pressure measuring device that corrects a detected value based on a correction curve corresponding to the characteristics of the device and outputs it as a measurement signal. The subband width is wider than the subband width as required, so that the entire measurable range can be covered, and each section is slightly shifted so that each section overlaps, and an appropriate correction curve is created for each section. storage means for determining and storing the correction curve; and selection means for selecting an appropriate one of the categories by inputting the lower and upper limits of the subband width of the measured value via the range setting means; Differential pressure measurement characterized by comprising a calculation means for reading a correction curve corresponding to the selected division from the storage means, correcting the detected value based on the called correction curve, and outputting a measurement signal. Configured the device.

As a result, (1) Since the subband of each category is narrower than the subband that covers the entire measurable range, it is possible to improve the correction accuracy relatively easily.

(2) Each category is divided into the required number of categories by shifting the temperature so that they can cover the entire measurable range and have some overlap, so by selecting one of the categories, Since the entire measurable range can be covered, the entire measurable range can be measured with high accuracy.

Therefore, according to the present invention, it is possible to improve the correction means of the differential pressure measuring device and realize a differential pressure measuring device that can perform correction with higher accuracy.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of main parts of an embodiment of the present invention, and FIG.
1, FIG. 3 is an explanatory diagram of the essential part of another embodiment of the present invention, and FIG. 4 is an explanatory diagram of a conventional example that has been commonly used. DESCRIPTION OF SYMBOLS 1... Storage means, 2... Selection means, 21... Range setting means, 3... Calculation means. Figure Figure

Claims (1)

[Claims] In a differential pressure measuring device that corrects a detected value based on a correction curve corresponding to the characteristics of the device and outputs it as a measurement signal, a subband width that is wider than the measurable subband width indicated as a rating is provided. In this way, the measurable range is divided into the required number of sections by being slightly shifted so as to cover the entire measurable range and so that each section partially overlaps, and an appropriate correction curve is determined for each section, and the correction curve is stored. a storage means, a selection means for selecting an appropriate one of the categories by inputting the lower and upper limits of the subband width of the measured value through the range setting means, and a correction corresponding to the selected category. A differential pressure measuring device characterized by comprising: arithmetic means for reading a curve from the storage means, correcting a detected value based on the read correction curve, and outputting a measurement signal.