CN201016784Y

CN201016784Y - Standard volume tube method flow gauge checking apparatus

Info

Publication number: CN201016784Y
Application number: CNU2006200133589U
Authority: CN
Inventors: 肖聪
Original assignee: Shenzhen Jianheng Industrial Automation System Co ltd
Current assignee: Gentos Mcasurement & Control Co ltd
Priority date: 2006-03-31
Filing date: 2006-03-31
Publication date: 2008-02-06
Anticipated expiration: 2016-03-31

Abstract

The utility model discloses a calibration device for flow meter which uses the standard pipe prover method; the device comprises an optical grating ruler equipped on the standard pipe prover, a pulse coding and counting circuit connected with the optical grating ruler and a pulse volume detecting circuit; a piston which is equipped in the volume pipe is measured with an operating length is L2 to L1 by the optical grating ruler; the flow pulse number gained by the pulse coding and counting circuit in the operating length is (Ns); the standard volume of the volume pipe is V and the corresponding optical grating ruler is provided with a length of L0 which are both fetched by strict demarcation of a high-precision meter; the proportion relation between the volume V of the standard volume pipe and the optical grating ruler length L0 is that K equal to that V multiplied with the difference between L2 and L1 and then the result divided by L0 and divided by the difference between Ns and 1. The utility model can not only greatly promote the calibration efficiency of a flow meter making use of the standard pipe prover method and simplify the circuit, but also can accurately correct the volume of detected section which further overcomes the error caused by the uneven flow pulse.

Description

Standard pipe prover method flowmeter calibration equipment

[technical field]

The utility model relates to a kind of calibration equipment of measuring equipment, particularly relates to a kind of ultrasound wave for measuring the standard pipe prover method flowmeter calibration equipment of medium.

[background technology]

Existing monophony ultrasonic flow meter comprises a pair of ultrasonic emitting and receiving trap and the flowmeter emission/receiving circuit that is arranged on outside the pipeline.A kind of flowmeter pipeline of prior art is a standard pipe prover, is used for measuring the fluid flow of pipeline of flowing through specially.In addition, be accurate measurement requirement, need the standard pipe prover calibration equipment that flowmeter is carried out verification, to obtain data and flowmeter is calibrated.

Present existing standard volume pipe calibration equipment, its standard paragraphs volume is changeless.The pairing flow pulse of its verified volume section is a decimal, gathers and calculate employing doubleclocking insertion.

Therefore, when instrument check, whenever obtain a checking data, must cover whole stroke, lose time, so work efficiency is lower.Particularly when doing the low discharge verification, allow the people accept especially.Simultaneously, the doubleclocking insertion that the collection of its flow pulse and calculating are adopted, circuit more complicated.

[utility model content]

In order to overcome the inefficient technical matters of prior art standard pipe prover calibration equipment verification, the utility model provides a kind of verification efficient high and simple standard pipe prover method flowmeter calibration equipment.

The utility model solves the problems of the technologies described above the technical scheme that is adopted: a kind of standard pipe prover method flowmeter calibration equipment is provided, comprises the grating chi that is arranged on the standard pipe prover; The pulse decoding counting circuit, the pulse volume testing circuit that connect the grating chi; The volume pipe inner carrier running length (L2-L1) of optical grating ruler measurement, the pulse decoding counting circuit obtains flow pulse number (Ns) in this length, the high-precision measurement instrument of volume pipe orthobaric volume V and its corresponding grating chi length L 0 usefulness is obtained through strict demarcation, and the proportionate relationship of the volume V of described standard pipe prover and grating chi length L 0 is: K=(V (L2-L1)/L0)/(Ns-1).

The further improvement that the utility model is done is: the proportionate relationship of described standard pipe prover Vp volume and orthobaric volume is: ((L2-L1)/L0) * V, wherein V is the orthobaric volume of standard pipe prover to Vp=.

The further improvement that the utility model is done is: described grating chi comprises separated by a distance to corresponding two optoelectronic switches of volume pipe inner carrier, two optoelectronic switch correspondences be the orthobaric volume (V) of volume pipe at this section, what the distance between them was corresponding is the length (L0) of grating chi.

With respect to prior art, the beneficial effect of the utility model standard pipe prover method flowmeter calibration equipment is: owing to do not need to cover whole stroke, the utility model not only can improve efficient, the simplification circuit of standard pipe prover method checking flow meter greatly, and the volume that makes test section obtained accurate correction, further overcome the error D that the unevenness of flow pulse is brought; In addition, test data can be offered the fabricator of flowmeter, the linearity of flowmeter be revised, to produce high-precision flowmeter.

[description of drawings]

Fig. 1 is the utility model standard pipe prover method flowmeter calibration equipment work schedule synoptic diagram;

Fig. 2 is the sequential synoptic diagram that utilizes the grating chi correction orthobaric volume of the utility model standard pipe prover method flowmeter calibration equipment;

Fig. 3 is the sequential synoptic diagram that utilizes the correction heterogenicity error D of the utility model standard pipe prover method flowmeter calibration equipment.

[embodiment]

The utility model be on the body of standard pipe prover, install additional can measure length and also have the very grating chi of high resolving power (1um), and attached with pulse decoding counting circuit, pulse volume testing circuit that connects the grating chi and the treatment circuit of managing foregoing circuit accordingly based on embedded data acquisition software.Described grating chi comprises separated by a distance to volume pipe inner carrier corresponding two optoelectronic switch VSW1, VSW2.

Optical grating ruler measurement goes out volume pipe inner carrier running length (L2-L1), the pulse decoding counting circuit obtains flow pulse number (Ns) in this length, volume pipe orthobaric volume (V) is demarcated through strictness and is obtained, and send host computer to draw by instrument coefficient of school flowmeter (K) or correction standard pipe prover volume V p above-mentioned data by the treatment circuit based on embedded data acquisition software.

The course of work of the utility model device is such: after being loaded onto by the flowmeter of verification, by serial communication interface given volume pipe piston running length is issued the volume pipe controller by upper industrial computer, send startup command simultaneously, volume pipe is brought into operation, when piston moves to optoelectronic switch VSW1, the running length of volume pipe controller opening entry piston, the flow pulse counter also begins counting, and write down the grating chi length (L1) of first pulse correspondence, in the piston operational process, whenever send a flow pulse, the volume pipe controller just detects the length of a grating chi.Its signal graph is seen accompanying drawing 1.When the given grating chi equal in length of the running length of piston and host computer, when promptly arriving optoelectronic switch VSW2, the flow pulse number (Ns) that the volume pipe controller is write down the pairing grating chi of last flow pulse length (L2) and amounted to, after of short duration time-delay, the commutation of control reversing control valve, piston turns back to starting point, prepares verification next time.Because the orthobaric volume (V) of volume pipe and its corresponding master grating chi length (L0) provide through strict the demarcation, therefore, are easy to just can draw by the instrument coefficient of school flowmeter (K), that is:

K＝(V(L2-L1)/L0)/(Ns-1)

More than, of the present utility modelly provide a kind of high-level efficiency, high-precision implementation method in order to obtain this parameter.

The utility model not only can improve efficient, the simplification circuit of standard pipe prover method checking flow meter greatly, and because when flow rate test, detect its corresponding grating chi length (L2-L1) with flow pulse, and the length of test section is decided to be the integral multiple in flow pulse unevenness cycle, make the volume (Vp) of test section obtain accurate correction (shown in figure two):

Vp＝((L2-L1)/L0)×V

And, further overcome the error D (shown in figure three) that the unevenness of flow pulse is brought.

The step that the heterogenicity error of flowmeter unevenness pulse is measured in this elimination is: in the flow pulse number (Ns) that records, when the heterogeneity recurrence interval is Integer N, non-homogeneous pulse is equivalent to the homogeneity pulse of same number n, if homogeneity pulse width of equal value is We, when the heterogeneity recurrence interval is not Integer N, non-homogeneous pulse non-equivalence is in the homogeneity pulse of same number n, and establishing non-equivalence homogeneity pulse width is Wu, and then heterogenicity error X is:

X％＝[(n×Wu)-(n×We)]/(n×Wu)

If further research, be equipped with necessary software and circuit, can also increase the scope of flow rate test, the homogeneity of sensed flow meter output pulse, perhaps the linearity of volume pipe is checked in the full sized pules of sending with standard signal generator, in addition, also test data can be offered the fabricator of flowmeter, the linearity to flowmeter is revised, and produces high-precision flowmeter.

Claims

1. standard pipe prover method flowmeter calibration equipment is characterized in that: comprising:

Be arranged on the grating chi on the standard pipe prover;

The pulse decoding counting circuit, the pulse volume testing circuit that connect the grating chi;

The volume pipe inner carrier running length (L2-L1) of optical grating ruler measurement, the pulse decoding counting circuit obtains flow pulse number (Ns) in this length, the high-precision measurement instrument of volume pipe orthobaric volume V and its corresponding grating chi length L 0 usefulness is obtained through strict demarcation, and the proportionate relationship of the volume V of described standard pipe prover and grating chi length L 0 is:

K＝(V(L2-L1)/L0)/(Ns-1)。

2. standard pipe prover method flowmeter calibration equipment according to claim 1, it is characterized in that: the proportionate relationship of described standard pipe prover Vp volume and orthobaric volume is:

Vp＝((L2-L1)/L0)×V

Wherein V is the orthobaric volume of standard pipe prover.

3. standard pipe prover method flowmeter calibration equipment according to claim 1, it is characterized in that: described grating chi comprises separated by a distance to corresponding two optoelectronic switches of volume pipe inner carrier, two optoelectronic switch correspondences be the orthobaric volume (V) of volume pipe at this section, what the distance between them was corresponding is the length (L0) of grating chi.