METROLOGICAL EXAMINATION OF DRAWINGS AND TECHNICAL DOCUMENTS

IN THE COURSE OF DEVELOPING TESTING EQUIPMENT

G. M. Shmulevich and A. I. Uskov UDC 389:620.1.05(083.75)

Improvement of products quality and of their utilization characteristics requires the solution of metrological-provision problems at all the stages of the product development, including the designing of their testing equipment. It is noted in [i] that deficiencies in metrological provisions for production begin, as a rule, from an incomplete and incorrect rep- resentation on drawings and technical documents~(DTD) of the requirements regarding the list of the products tested (measured) parameters, as well as measuring means and methods, and this reduces production quality in the long run.

Particular attention is now paid to the DTD metrological examination in order to raise the quality of developed and marketed products.

The DTS metrological-examination procedure to be used in the course of developing mea- suring equipment is described in this article. Metrological examination of these documents at the stage of the measuring-equipment development leads not only to a higher production quality, but it also reduces the materials and labor expenditure and the time required for developing and manufacturing products. The charts entitled "Technical assignments for plan- ning the measuring system of a test rack" (Table i) and "Table of measurements" (Table 2) were refined in the course of several years and provide the possibility of presenting in a technically competent manner the requirements for a measuring system and develop a system which would meet these requirements in the best possible manner and at the planning stage.

Metrological examination of DTDs is carried out by factory metrological service in strict conformity with the regulations of the State System for Ensuring Uniform Measurements (GSI), state standards, and normative-technical documents compiled on their basis.

The basic problems which are solved by the metrological examination of DTDs consist of determining the optimum list of the products' tested parameters by taking into consideration the products' metrological provisions; determining whether the products are suitable for test- ing, i.e., whether it is possible to ensure the testing of the products' given parameters dur- ing manufacture, installation, and testing; coordinating the specified measurement-precision indexes with the requirements for efficient and trustworthy testing; establishing complete and accurate requirements for the measuring equipment; determining the requirements in auto- matic measurements, the application of centralized testing machines, and automatic informa- tion-retrieval and processing systems with the application of computers; establishing the necessity for developing new measuring means and methods; ascertaining that the measuring means and methods were correctly selected; providing correct metrological terms and defini- tions of physical quantities and their units.

In order to solve these problems the metrological examination of DTDs is carried out when the technical assignments for the measuring system of the test rack are compiled and al- so when the system is developed.

Metrological inspection covers the technical assignments for designing the measuring sys- tem of the test rack (see Table i); the program and techniques for testing products on the test rack; drawings and assemblies for installing primary measuring transducers and measur- ing instruments with their auxiliary equipment; measuring-equipment computations; documents on nonstandard measuring equipment; test-rack measuring scheme with the appropriate chart (complete) (see Table 2); measuring-equipment (wiring) circuit ~ith the connections chart; assembly drawings for measuring-equipment boards; measuring-system electrical schematic;

Translated from Izmeritel'naya Tekhnika, No. 12, pp. 9-10, December, 1976.

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TABLE I.

Measured parameter

•0 measurement o range, dy- o ~ namic charac-

.~ teristic (param. o ~ ~ eters rate

~ of change, or frequency and

~o amplitude of pulsations,

~ o etc.) specified in the pro-

~> ~ gram or tech- o ~ nologieally ~ 8

!Tested medium, limiting param- eters at the point of mea- surement (tern- peratures, pres- sure, velocity, and other param- eters which affect the ef- fieienc.y of measuring equipment)

Measurement requirements Signaling and regu- lation requireme~nts

place where the primary measuring transducer is located or con- nected

manner of pre - senting measured information

degree of the measure- ments auto- mation

installed signaling and regu- lation

d o ~ o ~ o ~1 o

. . = ,

,~ '~"~ ~ 0 �9 ,.~-,~ ~ ~,~ 0

o o ~ ~ . ~ =

>

2

~'~ O

~

.o

~0

E

e~

o

~ g

TABLE 2.

Measured parameter

measurement range, dynamic characteristic

~ . o or frequency and (rate of change

~ amplitude of o = .~ pulsations, etc.), "~ o specified in the

program or tech- ~ nologically

o ~

o a

Tested medium, limiting param- eters at the point of mea- surements ( tem- perature, pres- sure, velocity, and other param- eters which affect the ef- ficiency of measuring equipment)

Measuring means

primar,f intermediate measuring instrument measunng measuring (installation) transducer transducer

=-~

n~ O ~

~o

> 0

0 0

O

O

O

O

D/3 e~

o o

O =~

m o o

o ~ ~ " ~ = ~

U/3 > o ~

Error

�9

v

0

O o E

O '.~.

,~ ~ 0 , ~

~ ~

O

~O

C

~O

specifications; and a list of purchased products. By adopting metrological examinations of drawings and technical documents at the enterprise it becomes possible to improve its pro- duction quality, solve the problems of metrological provisions at the stage of these docu- ments' drafting, before the testing equipment is manufactured, and as a result of this improve the quality of the designed products.

I.

LITERATURE CITED

A. M. Nikiforenko, Izmeritel. Tekh., No. 8 (1975).

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