ELIAS GmbH
Produktdokumentationen

Antialiasing is applied to raster graphics to reduce unwanted staircase effects. “Supersampling”, a process for smoothing edges, is used in an intermediate stage to first generate a raster graphic with a higher resolution. The height and width are multiplied by the specified quality level. The graphic is then scaled down using the selected interpolation algorithm. This method increases the memory consumption and the runtime for the export.

The following categories can be assigned in infra CONVERT:

Category	Description	References
Standard characteristic	Characteristic that is not assigned to any of the following categories.	–
Special characteristic	A critical characteristic that deserves special attention. If the implementation of the characteristic does not correspond to the drawing specifications, a potential risk to functions (operational safety, interchangeability, service life, etc.) has to be expected to a great extent. Example of tagging:	–
Auxiliary measurement	Measurement that is not required for the geometric determination of a part and is not considered an integral part of the contract. Example for the tagging:	• DIN EN ISO 129-1
Rough measurement	Measurement that refers to the initial state of an object. Example for the tagging:	• DIN 406-10
Theoretically accurate measurement	Measurement for indication of the geometrically ideal (theoretically precise) position or shape of the dimensioned shape element. Example for the tagging:	• DIN EN ISO 129-1
Test measurement	Measurement that must be given special attention when determining the extent of the test / test accuracy. Example for the tagging:	• DIN 406-10

The business processes within manufacturing companies are controlled using management systems. Today, these are almost completely realized with powerful information systems. Enterprise resource planning (ERP) is the higher-level control system of a company. The efficient use of resources is planned and controlled with this, see the following figure; resources can include capital, personnel, resources, infrastructure, materials, etc.

The personnel resources (management, process engineers, maintenance personnel, machine operators, etc.) and material resources (production means: manufacturing equipment, measurement devices, transportation means, packaging materials etc.) on the production level must be managed preferably in real time due to the continuously increasing complexity, speed and quality requirements of adequately efficient management information systems. The ERP system is unsuitable for process-oriented, process-specific tasks due to the requirements of company-wide data management (size, “inertia”). Task-related management systems are therefore interposed between the corporate management and production level. Collectively these are referred to as the Manufacturing Execution System (MES). MES functionalities support, among other things, detailed planning, implementation and control of production processes.

Company objectives relating to quality assurance and enhancement are today being increasingly supported by Computer Aided Quality Management (CAQ). Quality-related parameters can be analyzed and documented along the entire product life cycle in order to derive corrective measures from the results if necessary. Therefore, they are an important instrument in the MES.

Quality-relevant demands on a product (individual component, module) are essentially of a geometric and material nature. The geometry of a workpiece (or a module) is determined by the creation and modification (transformation, reproduction, referencing) of construction elements on a step by step basis (also: geometric primitives, shape elements, user defined features). Creation and modification operations require special parameters for unique identifiability, such as diameter and length of a cylinder. These are presented on the technical drawing together with other identifying information, such as material and surface specifications. The manufacturing and testing processes are based on these characteristics, as they are especially referred to in testing.

A differentiation is made between variable and attributive characteristics for test tasks here:

Variable characteristics are requirements that can be quantified. These relate to values that are associated with a tolerance and can be queried with a numerical value and a unit (→(Size-)measurements).

Attributive characteristics can only be assessed qualitatively. They are queried with fulfilled/not fulfilled or OK/NOK. Examples include “All edges deburred.”, “Pin holes drilled in composite.”, “Protection class IP 44”.

Characteristics can also be sorted by →Classes.

The specification of →characteristics in the technical drawings follows defined rules. Such rules are laid down in international and national norms, but also company publications (factory standards). Misunderstandings are avoided between the customer and the supplier when reference is made to rules of interpretation, despite a reduction in the documentation effort required. A class refers to a rule and thus specifies the context in which the characteristic properties are to be understood.

The classes listed at this point, sorted into the following groups, can be assigned in infra CONVERT. The classes relate to recognised standards (see “References” column). Unless otherwise stated, the unit of measurement always applies to tolerance limits as well.

Note Class designations and associated measurement units can be changed by your CAQ system provider or administrator, see Administrator’s Guide infra CONVERT > Configuration and Import > "CharacteristicClasses” parameter file. We would be pleased to add another class should you require it.

• Classes: lengths and angles
• Classes: simple geometries
• Classes: geometric tolerance (shape, direction, position and run)
• Classes: gearwheels
• Classes: edge conditions
• Classes: surface parameters
• Classes: material properties
• Classes: physical sizes
• Classes: Further information

Note Sorting by groups will also be applied in the software in the future.

Structure of drawing entries

The requirements of surface properties are entered into the drawing using a graphical symbol. The position and structure of the fields for individual entries is determined as follows (cf. DIN EN ISO 1302:2002-06):

Class	Symbol/​tag	Description	References (Selection)	ID
				ELIAS	K2009
Smoothing depth (peak)		Vertical parameter of the roughness profile. Height of the largest profile peak within the measuring section ln. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	96	–
Smoothing depth (valley)		Vertical parameter of the roughness profile. Depth of the largest profile valley within the measuring section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	97	–
Average roughness depth		Vertical parameter of the roughness profile. Sum of the height of the largest profile peak and the depth of the largest profile valley within a single measurement section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	23	150
Maximum average roughness depth		This parameter is a variation of the regular requirement for the average roughness depth. The specified variable is not to be interpreted with the 16 % rule, but with the maximum value rule. “Rmax” is also commonly used as an indicator. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	31	158
Average profile element height		Vertical parameter of the roughness profile. Average value of the height of the profile elements within a single measuring section. A profile element is formed based on a consecutive profile valley and a profile peak. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	98	–
Total height		Vertical parameter of the primary profile. Sum of the height of the largest profile peak and the depth of the largest profile valley within the section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	26	153
Total height		Vertical parameter of the roughness profile. Sum of the height of the largest profile peak and the depth of the largest profile valley within the section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	93	–
Total height		Vertical parameter of the waviness profile. Sum of the height of the largest profile peak and the depth of the largest profile valley within the section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	30	157
Arithmetic average roughness value		Vertical parameter of the roughness profile. Arithmetic average of the sums of the amplitude values within a single measuring section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	25	152
Quadratic average roughness value		Vertical parameter of the roughness profile. Quadratic average of the amplitude values within a single measuring section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	99	–
Profile skew		Vertical parameter of the roughness profile. Measurement for the asymmetry of the amplitude density curve within a single measuring section. The amplitude density curve reflects the amplitude part in each horizontal sectional plane. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	100	–
Profile steepness		Vertical parameter of the roughness profile. Measurement for the steepness of the amplitude density curve within a single measuring section. The amplitude density curve reflects the amplitude part in each horizontal sectional plane. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	101	–
Average groove width		Horizontal parameter of the roughness profile. Average value of the profile elements within a single measuring section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	102	–
Peak count		Horizontal parameter of the roughness profile. Number of average widths of the profile elements in a predefined length, standard 10mm. Standard measurement unit –	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	103	–
Average profile gradient		Mixed (vertical and horizontal) parameter of the roughness profile. Quadratic average of the local profile gradient within a single measuring section. Standard measurement unit Micrometres	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	104	–
Material share		Parameter from the Abbott-Firestone curve (AF curve) of the primary profile. Material share in a cutting line height relative to the share in a reference cutting line height. The AF curve reflects the cumulative frequency of the amplitude values within a measuring section. Standard measurement unit Percent	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	70	160
Material share		Parameter from the Abbott-Firestone curve (AF curve) of the roughness profile. Material share in a cutting line height relative to the share in a reference cutting line height. The AF curve reflects the cumulative frequency of the amplitude values within a measuring section. Standard measurement unit Percent	• DIN EN ISO 4287:2010 • DIN EN ISO 4288:1998 • DIN EN ISO 1302:2002	105	193
Core roughness depth		Parameter of the roughness core profile. Total height of the roughness core profile within the measuring section. The roughness core profile is the roughness profile without projecting peaks and deep valleys. Standard measurement unit Micrometres	• DIN EN ISO 13565-2:1998 • DIN EN ISO 1302:2002	27	154
Smallest material share		Parameter of the roughness core profile. Material share in percent at the level of the cutting line, which separates the projecting peaks from the roughness core profile. The roughness core profile is the roughness profile without projecting peaks and deep valleys. Standard measurement unit Percent	• DIN EN ISO 13565-2:1998 • DIN EN ISO 1302:2002	71	161
Largest material share		Parameter of the roughness core profile. Material share in percent at the level of the cutting line, which separates the deep valleys from the roughness core profile. The roughness core profile is the roughness profile without projecting peaks and deep valleys. Standard measurement unit Percent	• DIN EN ISO 13565-2:1998 • DIN EN ISO 1302:2002	72	162
Reduced peak height		Average height of the projecting peaks above the roughness core profile. The roughness core profile is the roughness profile without projecting peaks and deep valleys. Standard measurement unit Micrometres	• DIN EN ISO 13565-2:1998 • DIN EN ISO 1302:2002	28	155
Reduced groove depth		Average depth of the profile valleys below the roughness core profile. The roughness core profile is the roughness profile without projecting peaks and deep valleys. Standard measurement unit Micrometres	• DIN EN ISO 13565-2:1998 • DIN EN ISO 1302:2002	29	156
Base roughness depth		Vertical parameter of the roughness profile. Amplitude value of the third highest profile peak from the third largest profile valley. Standard measurement unit Micrometres	Not officially standardised.	32	159
Additional surface specifications	–	Machining allowance, position and orientation of surface grooves. Standard measurement unit –	• DIN EN ISO 1302:2002	118	–
Layer thickness	–	Material thickness of one or more coatings over a surface. Standard measurement unit Millimetres	–	64	260

A →technical drawing is referred to as a collective drawing if several variants of a similar component or assembly, each with its own part number, are grouped together in this document. (see DIN 30:2002-12)

Usually only one of the component variants or a generic component, which contains all properties in one characteristic, is displayed graphically. The variable properties are indicated with a code letter (also: “dimension letter”) and called up in a table.

Various data formats have been established for the digital exchange of →technical drawings. Each data format transports at least the graphic information of a drawing printed on paper. In addition, vector formats and especially specially developed drawing data formats store information that facilitates automated readout by computer programs.

Basically, a technical drawing is constructed according to largely internationally defined standards from linear graphic elements as well as text elements. The reader derives the meaning from the arrangement of the elements in relation to each other. However, this kind of interpretation work can only be implemented by software to a very limited extent. For this reason, additional information is stored in drawing data formats, which indicates to a software that the elements belong together and what they mean.

The suitability of different data formats for automated interpretation can be generalized as follows:

In infra CONVERT, a CAD exchange format is the minimum requirement for fully automatic feature recognition.

Vector graphic formats, on the other hand, store graphic elements as unique, mathematically described graphic primitives. The latter mean basic geometric elements such as straight lines, arcs, and splines, as well as surfaces such as circles, polygons, and spline surfaces. Texts are stored either as polylines or with the help of character encoding (see also →Font).

In infra CONVERT, character-coded texts or embedded fonts are a prerequisite for automatic feature recognition.

Non-graphic information is specified in technical drawings using characters. Characters can be letters, numbers, diacritics, punctuation marks, and additional graphic symbols. Due to their frequent repetition, they are grouped into a stock, the character set. In electronic data processing, characters are uniquely identified by coding in a character set. Numerous standards exist worldwide for character coding. “ASCII” is an example of a very small set, “Unicode” an example of a very large set to which characters are continuously added. A digital character set is called a font. A font file usually contains a character set with a uniform graphic design.

In addition to the purely visual representation of characters, the unambiguous definition of characters is important for the automatic analysis of technical drawings. PDF files are generally used to displaying characters correctly. This is because the character definitions used are saved (embedded) in the file. This is (unfortunately) different with the CAD exchange formats DXF, DWG and IGES. In them only the references to characters are stored in font files. The font files are therefore required for correct display.

Significance for infra CONVERT Fonts are protected by copyright. In most cases, the rights of use are only granted for a fee. The number of fonts used by CAD systems is immensely high. Supplying these fonts would disproportionately increase the cost of infra CONVERT licenses. For this reason, infra CONVERT replaces fonts not installed on the computer with visually similar fonts when loading drawing files. If this is the case, a note message is issued.

A Layer (also: “foil”) is a structuring aid in drawings and combines objects or drawing elements. Layers are placed on top of each other like transparent slides on an overhead projector, so that the content combined in this way shows the overall result. Layers have, among others, the properties show/hide (enabled/disabled), printable/not printable. If contents of a layer are not needed at a certain time, it can be hidden. Several drawing variants can be saved in one document or file, for example texts in several languages.

(Size-) measurements are used to specify geometric and other physical properties of a product (→variable characteristic). They are expressed as the multiple or part (numerical value) of a reference value (unit of measurement):

The following graphic explains some of the terms used in infra CONVERT for linear measurements and measurement tolerances.

In infra CONVERT, the unit of measurement is assigned to a characteristic using the characteristic class. The following units with attachments for decimal parts and multiples from different unit systems are available.

Note Your CAQ system provider or administrator can change class names and associated units of measurement for you, see Administrator's Manual infra CONVERT 2019 > Configuration and Import > Parameter File “CharacteristicClasses”.

Note Your CAQ system provider or administrator can change class names and associated units of measurement for you, see Administrator's Manual infra CONVERT > Configuration and Import > Parameter file "CharacteristicClasses".

The numerical precision is relevant for the representation of numerical values. If a technical fact is described with numerical values, usually in the form of physical quantities or →measurement sizes, the accuracy of the displayed number should be in the same order of magnitude as the inaccuracy of the measure itself.

For example, the maximum inaccuracy range of the value 23, if no further information is available, is 22.5 to <23.5. Finally, the value may have resulted from a rounding operation. The last significant digit, here the “3”, is the digit that was rounded or may have been rounded.

The number of significant or relevant digits in a decimal number can be identified as follows (see also “DIN EN ISO 80000-1:2013-08, Chapter 7.3.4 Deviation and uncertainty”):

1. The number is viewed from left to right. The first non-zero digit is the first relevant digit.
2. Following zeros are also relevant, especially if they are to the right of the decimal point.
3. Zeros to the left of the comma are only relevant if at least one other digit, including zero, follows to the right of the comma.

The numerical accuracy common in technology (“slide rule accuracy”) is achieved by rounding a value so that three significant digits remain. Unless the first significant digit is a one, four significant digits should remain.

Even if it is technically possible, a project should always only refer to an object that is subject to a test and, if necessary, follow-up tests. This may be, for example, the initial sampling of a product and its subsequent re-sampling (first-piece approvals, requalifications).

By using a simplified specification, requirements for a geometry element are specified in simplified form and explained elsewhere in the drawing, for example next to a view or near the title block. This type of specification can be useful if there is not enough space available in a view or if a specification applies to several separate geometry elements and is specified more than once.

The following example shows the principle for surface specifications and geometric tolerance specifications.

→Characteristics are derived from drawing entries. If a drawing entry collectively specifies several similar geometric elements of a component and each of these geometric elements is to be checked individually, further individual characteristics are derived from the original characteristic. In infra CONVERT three possibilities are available for this.

The ISO GPS standard system based on DIN EN ISO 8015 regulates the language with which requirements for the geometry of a product are communicated. With an entry – constructed from “specification elements” – on the technical drawing, a specification operator in the standards system is invoked. A specification operator collates rules (“operations”) that are used to allow all the contract parties to understand the requirements of a geometric element or the relationship between geometric elements.

The principle of standard setting applies here, namely the “default principle”. Unless indicated through the addition of supplementary information in the contract agreement, the specification operator only includes default operations in a fixed order according to ISO standards. The default is chosen so that the operations approximately correspond to the most commonly used procedure and conventional understanding in practice.

In the following image, the concept is illustrated using the shaft geometric element with a nominal diameter of 20 mm as an example. At first only the defaults specification is considered, as shown on the left side. The drawing entry specifies a “linear size element” according to DIN EN ISO 14405-1 of the type “cylinder”. The default specification operator demands consideration of the “local two-point size”: All independently determined individual distances from opposite lying points must lie within the tolerance range, i.e. according to tolerance code “h9” of DIN EN ISO 286-1 at an interval of between 19.948 mm and 20 mm. Five arbitrary two-point sizes on the non-ideal surface model are represented as a geometric equivalent.* One suitable means of verification (“verification operator”) for this specification would be to carry out a check using a go/no go gauge: 1) Pass check (go): Is the maximum material size exceeded?; 2) Fail check (no-go): Is the minimum material size undershot?

The deviation from the default setting can be identified using suitable specification modifiers (and/or abbreviations). In this way a “special specification operator” is obtained. In this example, the “E in circle” modifier symbol sets the envelope condition. The envelope condition requires that the evaluated geometry lies in an enveloping cylinder 20 mm in diameter and that all two-point sizes are greater than or equal to 19.948 mm. A suitable verification would be to test using a ring gauge or to carry out a no-go test using a go/no go gauge.

Below are examples of modifier text symbols with their meanings, such as those that can be assigned to a characteristic as property “modifiers” in infra CONVERT.

A characteristic identifier consists of the graphic characteristic symbol and the, mostly numeric, characteristic number. A clear correlation to the test characteristic is established together with the part number of the technical drawing. Usually when the characteristic attribute is changed (due to a change in the drawing) the same characteristic number remains, the number is blocked on deletion and the next previously unused characteristic number is assigned once a characteristic is added.

→Characteristic categories, for example, can be made visible in infra CONVERT by assigning them with one of the following six stamp symbol shapes as well as a symbol color.

A test plan is exported from infra CONVERT, e.g. for further processing in a →CAQ system, in the form of an exchange format (JSONV1 or DFD, see Administrator Guide infra CONVERT > Export).

A test plan can contain the following information, for example:

The Tolerance table is the section of a norm that governs the general dimensional, shape and/or positional tolerance for workpieces. The limit values are assigned to nominal dimensional ranges within the table, whereby the limit values are further graded based on the Tolerance classes (also: Tolerance grades or Tolerance series), e.g. “fine, medium, coarse, very coarse” or “intrinsic, not intrinsic”.

General tolerances for length measurements, angle measurements and edge dimensions (curve radii and chamfers) can be automatically assigned to the nominal dimensions in infra CONVERT based on the loaded tolerance tables.

Legal note You do not acquire any user rights to the tolerance tables contained in the infra CONVERT software upon purchase. You yourself must obtain lawful access to the corresponding texts, such as the norms and other agreements. You have the option of creating tolerance tables yourself (see Administrator Guide infra CONVERT > Configuration and import > Tolerance tables) or have them created by us based on your data.