Performance sampling verification method for propeller current meter

Abstract

The invention discloses a performance sampling verification method for a propeller current meter. According to the method, a relation of propeller helical angles alpha, an inner friction moment M of a rotary supporting component and the verification performance of a propeller current meter is established, and aiming at mass production, the values of the alpha and the M are precisely determined; the alpha values are finely grouped, and according to a method of non-random quota sampling for the totality, random sampling for groups and weighted statistics for a result, a sample machine is precisely verified under a still water condition; meanwhile, theoretical calculating values are supplemented in verification for analysis and reference for correcting errors in time; through the measures, the total precision of the sample machine is guaranteed to be high; meanwhile, medium high and low speed standard linear formulas are used to ensure that the use of a hydrological testing current meter is precise and convenient; in production, the defects of the traditional mass production are overcome, and the workloads of verification works, labor intensity, power consumption, equipment overhaul and maintenance, and the like are reduced by 2/3; and the operation of verification procedures is scientific and normative and conforms to a modern production mode and a national standardized technical policy, so that the method has the advantages of better scientific, social and economic benefits.

Description

technical field [0001] The invention relates to a method for sampling and verifying the performance of a propeller current meter for hydrological testing of rivers. Background technique [0002] 1. Performance verification of flow meter [0003] The current meter is used to measure the speed of river water flow, and its performance verification is based on the principle of relative motion of objects: assuming that the river flow is a static water body, when measuring the flow, the current meter fixed on the measuring point is a moving body. The verification equipment designed according to this is a straight open channel with long water tanks, and tracks are laid on both sides of the bank. T run, and at the same time detect the corresponding speed n output by the current meter, assuming the speed of the test vehicle V T is the standard input quantity V, that is, V T =V, through the verification of the flow meter verification tank, determine the medium and high speed perfor...

AI Technical Summary

Problems solved by technology

[0007] 2. Problems existing in mass production verification of current flow meters

According to Newton's third law: the action force and the reaction force are generated at the same time and are interdependent; when the waves aroused by the instrument hit the surrounding tank walls, they will be reflected and act on the instrument. After repeated superposition, the situation is very complicated and does not conform to the flow velocity Therefore, the verification system does not have the national measurement legal accuracy, that is, the verification accuracy of the flow meter cannot be guaranteed, and there are the following problems:

There is no way to count the error and quantity of type b) and type c) false detections, and they have been found in the inspection and verification;

[0011] (3) Assignment deviation: There are certain differences in the assignment of verification results between different tanks and the same tank at different times, which is unfavorable for flood control, irrigation, national economic water resource utilization, and hydrological flow reorganization;

[0012] (4) Labor intensity: Batch production inspections require overtime and overtime work. Workers are exhausted. In order to complete the production quota on time, workers have short rest time and even have to eat on the...

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