| LECHNER, Jiøí | |
SOME REMARKS ON QUALITY SYSTEM IN SURVEYING AND METROLOGY |
Proceedings of Research Works 1998. - Roè.44. - Zdiby : VÚGTK, 1998. - S.77-81. - ISBN 80-85881-10-1 |
1. Introduction
One of the prerequisities for a perfect function of the common market in surveying, like in other
technological branches, is the unification of regulations along with amendments of quality management
systems aiming at a unity in measuring techniques and equipments including their accuracies. For the
measurement a correctly defined unit of the measured quantity is necessary, an appropriate measuring
technique must be used, an adequate measuring equipment must be available and, last but not least, the
human factor, represented by a person performing the measurement, must be taken into account.
Metrology is the science dealing with measurement including all its theoretical and practical aspects
regardless of both the uncertainty level and the relevant domain of science or technology (definition and
remark 2.2 taken from the ÈSN 01 0115). Therefore metrology must be taken as a theoretical basis of
any calibration or confirmation activity performed in arbitrary branch.
2. General on Standards
From the point of view of standardization there are standards inherent to metrology and its scope, such
as terminology, quantities and units, measuring errors, measures and measuring equipment. Each
international standards organization like
BIPM
IEC
IFCC
ISO
IUPAC
IUAPAP
OIML |
Bureau international des poids et mesures
International Electrotechnical Commission
International Federation of Clinical Chemistry
International Organization for Standardization
International Union of Pure and Applied Chemistry
International Union of Pure and Applied Physics
Organisation internationale de métrologie légale |
has its own system of classification of standards which, in general, is not related to the scope of the
standard. Usually it is a serial number of the first publication of the corresponding standard. At present
the translations of the standards of the international organizations ISO and IEC are preferred in the Czech
Republic and/or their modifications are being made resulting in European Standards EN.
In case when the foreign standards are taken over by translation, their original labelling remains
unchanged, only "ÈSN" is put in front of their original labels. If the standards are ordered according to
their origins, then the standards ÈSN ISO, ÈSN IEC, ÈSN EN and the present ÈSN will stand
independently and the search for a certain group of mutually related standards will get more difficult.
More practical is probably the ordering according to the original Czech labelling because it is directly
related to the content of the corresponding standard.
If it is stated that the standard "contains binding provisions" then it means that this standard (in the
entire scope or in some parts) is getting obligatory according to the decision of an approved governmental
authority in the sense of §3 and §4 of the Act No. 142/1991 Dig. These provisions will have been binding
till 31 December 1999 (§21 of the Act No. 22/1997 Dig. "Technical Demands on Products").
The international standards can be taken over by some of the following ways:
- "Taken over by translation"
- "Taken over by adopting the original version"
- "Taken over by approval for direct use"
- "Taken over by announcement in the Bulletin"
and four identity indications with an international standard can be distinguished
"idt"
"egv"
"neg"
"mod" | identical
equivalent
unequivalent
modified . |
In the Czech Republic the Technical Standardization Commissions (TSC) have been established
to follow the process and results of the international standardization. The Research Institute of Geodesy,
Topography and Cartography has its representatives in the TSC No. 24 "Geometrical Accuracy of Building
Constructions" and TSC No. 122 "Geomatica".
3. Review of Standards
The quality related international standards have an essential impact on the level of metrology in an
organization. The series of standards ÈSN EN ISO 9000, in which all requirements for measuring and
testing devices and their uniformity are specified in a unique way, can serve as an example. From this
series of standards the following should be recalled:
ÈSN EN ISO 9001
ÈSN EN ISO 9002
ÈSN EN ISO 9003
ÈSN EN ISO 9004-1 | Model of quality assurance in design, development, production, installation and service
Model of quality assurance in production, installation and service
Model of quality assurance in final inspection and testing
Quality management and quality system elements - Part 1: Guidelines |
A number of other standards link up the standard series ÈSN EN ISO 9000. From the point of view
of metrology the standard ÈSN ISO 10012-1 Requirements on quality assurance of measuring
equipments - Part 1: Metrological confirmation system for measuring equipments is important. The
metrological confirmation includes, among others, the calibration, any necessary adjustment or
adaptation with a subsequent re-calibration. The standard ÈSN ISO 10012-2 dealing with the measurement process is under preparation.
In measuring geometrical elements the following parameters have to be checked:
– dimension tolerances and deviations
– geometrical tolerances (of the shape, direction and position).
In tolerancing the standard ÈSN ISO 8015 Fundamental tolerancing principles must be respected.
The problems related to the metrological baselines are solved in the standard ÈSN ISO 5459.
The dimension tolerances are based on the standard ÈSN EN 20286-1 ISO system of limits and
fits, Part 1: Basics of tolerances, deviations and fits (valid for the dimensions up to 3,150 mm). For the
tolerances and fits of larger dimensions (up to 10,000 mm) the standard ÈSN 01 4203 is valid. If the
length and angular dimensions are not toleranced in technical drawings, the standard ÈSN ISO 2768-1
Non-prescribed limit deviations of length and angular dimensions should be used.
The geometrical tolerances, which determine the deviation of an element from its shape, direction
or position, are given in the standard ISO 1101 Technic geometrical tolerancing - Tolerances of form,
direction, location and run-out. Generalities, definitions, symbols, indications on drawings. If the
geometrical tolerances are not prescribed for individual elements in technical drawings, the standard
ÈSN ISO 2768-2 General tolerances, Part 2: Non-prescribed geometrical tolerances should be
followed.
In the following a survey of some standards related to the geometrical accuracy in building
construction is given.
ÈSN ISO 8322-1
ÈSN ISO 8322-2
ÈSN ISO 8322-3
ÈSN ISO 8322-4
ÈSN ISO 8322-5
ÈSN ISO 8322-6
ÈSN ISO 8322-7
ÈSN ISO 8322-8 |
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 1: Theory (73 0212)
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 2: Measuring tapes
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 3: Optical levelling instruments (73 0212)
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 4: Theodolites (73 0212)
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 5: Optical plumbing instruments (73 0212)
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 6: Laser instruments (73 0212)
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 7: Instruments used for setting-out (73 0212)
Geometrical accuracy in building industry - Determination of accuracy of measuring instruments - Part 8: Electronic distance- measuring instruments up to 150 m (73 0212). |
4. Metrological Assurance of Geodetic Instruments and Measuring Equipments
The Research Institute of Geodesy, Topography and Cartography is appointed by the Czech Office for
Technical Standards, Metrology and Testing as a National Metrology Center (NMC). The compliance
with a measurement standard is in this NMS ensured by means of a HeNe laser 633 nm. The NMC
VUGTK currently provides the confirmation and/or calibration of the following measuring equipments:
- invar gauge length measurement standards
- invar tapes
- invar base parallactic rods
- steal meters
- measuring tapes
- electro-magnetic distance meters
- levelling instruments
- gauge bars and other special gauge measuring equipment
- clinometers
- slide gauges (sliding calipers)
- theodolites (optical, electronic)
- optical plumbing devices
- compasses
4.1 Baselines for Confirmation of Electronic Distance Meters
An essential condition for an efficient use of electronic distance meters in practical surveying is, like with
other length measuring equipments, a sufficiently accurate realization of the length unit. With the
electronic distance meters these length units are set up during their construction. This initial set up is
always done with a certain deviation depending on the construction and on the accuracy category. The
detection of this deviation is an integral part of the process of realization of the above mentioned length
unit and its determination is directed by generally binding regulations to ensure the uniformity and
traceability to the national measurement standard. The deviation, if it is determined with an accuracy
corresponding with the accuracy of the electronic distance meter, is used, if necessary, as a correction
of measured distances, otherwise it represents a necessary information for its possible neglecting in lower
accuracy measurements.
The aim of the calibration of electronic distance meters on the calibration base line is the determination
of the addition constant and of the multiple constant along with corresponding accuracy
characteristics. The constants can be determined only after the necessary atmospheric corrections had
been introduced.
4.1.1 Geodetic Length Calibration Baseline Hvìzda
The pillars Nos 1 to 7 of the calibration baseline, which serves for the confirmation and/or calibration
of the electronic distance meters, are located along the boundary line between the southern and the main
park path in the deer-game park in Prague 6, Bøevnov. The baseline points are monumented by concrete
blocks 40×40×110 cm with the bronze pegs with centric little holes of the diameter of 1.5 mm. The
measurement of the individual baseline sections was carried out by invar tapes in all combinations in
compliance with the primary length measurement standard (the standard of the Czech Metrological
Institute, Laboratory of Primary Metrology). The accuracy estimate resulting from the least squares
adjustment is characterized by the standard deviation less than 1.0 mm. The total length of the baseline
is 960.8725 m.
4.1.2 Geodetic Length Calibration Baseline Koštice
The pillars Nos 1 to 12 of the calibration baseline are located nearby the village Koštice in North-West
Bohemia along the road directed to the north. The monumentation is realized by deep-borehole foundations of the concrete pillars down to the depths of about 5 - 9 meters. The pillars are equipped with the
force centering and with a feasibility for the elimination of inherent deviations. The least squares
adjustment gives the standard deviations of the lengths of individual sections less than 0.5 mm. The
baseline length is 1,450.0105 m.
4.2 Baseline for Confirmation of Levelling Instruments
The main goal of the confirmation is to verify the fulfilment of the essential condition of the levelling
instrument, i.e. that the optical axis must pass through the center of the eye-piece reticule. If this
condition is not fulfilled, i.e. if the deviation is greater than 0.05 mm/1 m of the sightline, an adjustment
of the levelling instrument must be done. The baseline is located directly in the metrological laboratory
of the NMC in the VUGTK.
4.3 Azimuthal Baseline for Confirmation of Angular Measuring Instruments
(Theodolites, Gyrotheodolites and Compasses)
The main point for the confirmation and/or calibration of the angular geodetic instruments is located
in the area of Židovské pece (Jewish Ovens) in Prague 3. It is monumented by a concrete block
20×20×80 cm with a bronze peg with a centric hole of the diameter of 1.5 mm. The individual directions
of the azimuthal standard (4 directions) are regularly distributed over the whole circle (400 g) and
signalized by measuring marks on the walls of buildings.
The orientation directions were observed independently by two observers in different times using
the theodolites Wild T3. Each measurement was carried out in six full observation sets (four directions
of the azimuthal baseline and additional directions to the points of the Local Triangulation Network
Praha and of the Local Detailed Horizontal Network Praha). The results of angular observations were
oriented to the south-bearings of the connection points of both above mentioned local networks.
An average absolute value of the correction of the connecting direction is 1.4 arcsec which documents
a very good quality of the connection measurements. For the conversion of the south-bearings to the
azimuths the meridian convergence was also determined. However, it does not comprise an average
rotation of the triangulation network.
5. Conclusion
Considering the §11 of the Act on Metrology and implementing quality management systems some
organizations, in the first place those cooperating with foreign investors, are building their internal
metrological guidelines (quality systems) and request from the suppliers of surveying works confirmations or calibrations of their measuring equipments. It must be said that in surveying the §11 of the
Act, i.e. a possibility of charging the suppliers with a compulsory confirmation using also other (branch)
regulations, has not been fully used till now.
Naposledy aktualizováno: 21.8.1998
Dotazy a pøipomínky k této WWW stránce na Milan Talich, Alexandr Drbal.
