ruler
Enable an agent to recognise a ruler, assess whether its scale and edge suit a task, and use it to measure or mark linear distances.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a ruler, assess whether its scale and edge suit a task, and use it to measure or mark linear distances.
A ruler is a physical measuring tool with a graduated scale for determining linear dimensions, commonly incorporating a straight edge for guiding drawn or scribed lines.
It can be Measure a linear distance by aligning endpoints and reading their scale positions.; Transfer a specified distance onto a workpiece or drawing.; Guide a marking tool along an assessed straight edge.; Select a scale and placement method appropriate to the required units, span and reading detail.; Inspect graduations, ends and edges to identify unusable regions or tasks.; Compare scale intervals against a suitable reference and record the resulting evidence..
Distinguishing features
Has an ordered set of graduations representing linear distances along a strip or bar; an ungraduated straightedge lacks this measuring scale.
Supports reading distance by aligning endpoints with scale positions, without the movable jaws or spindle characteristic of calipers and micrometers.
Presents its measuring span along the body rather than requiring a graduated tape to be pulled from a reel.
For direct measurement, the scale represents physical distance in stated units; reduction or enlargement scales require an explicitly identified conversion.
Belongs to the physical-tool sense of 'ruler', rather than the social role of a person who governs.
Scope
+ Graduated scales, units, divisions, numbering and zero placement
+ Body geometry, material, flexibility and working edges
+ Direct length measurement and transfer of measured distances
+ Straight-line guidance where the ruler provides a suitable edge
+ Condition and evidence of suitability for a stated measurement task
- Rulers as sovereigns or governing roles
- Ung raduated straightedges whose primary function is line guidance or straightness checking
- Retractable measuring tapes and their reel mechanisms
- Calipers and micrometers with movable measuring contacts
- Drawing-scale conversion conventions and dedicated scale-rule models
- Product catalogues, manufacturers and individual measurement records as independent models
Characteristics
- Scale units
- Units printed on each scale, such as mm, cm or in; unknown if unidentified Prevents readings from being interpreted in the wrong unit.
- Graduated range
- Lower and upper labelled or established scale values in the scale's unit Determines whether the target distance can be read in one placement.
- Smallest graduation interval
- Distance between adjacent smallest divisions, recorded separately for each scale Constrains reading detail without establishing measurement accuracy by itself.
- Zero offset from physical end
- mm or another stated length unit Determines whether the ruler's end can serve as the measurement origin.
- Scale-to-length mapping
- Direct physical length, scaled conversion, unidentified Prevents a drawing-scale reading from being mistaken for an actual physical distance.
- Body dimensions
- Overall length, width and thickness in mm Affects reach, placement in confined spaces and separation between marks and the measured surface.
- Body material and construction
- Observed or documented material; transparent or opaque; single-piece or articulated Helps explain visibility, handling and potential deformation.
- Flexibility
- Rigid, semi-flexible, flexible, unestablished Determines whether bending during placement can affect the intended measurement.
- Working-edge condition
- Intact, nicked, worn, bowed, uninspected A damaged edge may be unsuitable for guiding a straight line even if the scale remains readable.
- Scale legibility
- Readable throughout, partly obscured, partly worn, unreadable Identifies which portions of the scale can support an unambiguous reading.
- Verification evidence
- Linked comparison, calibration or manufacturer specification identifying the ruler and applicable conditions Supports a task-specific accuracy judgement beyond the appearance of fine graduations.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.ruler
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 15 findings · 27 questions.
Ruler identity and boundary Establishes which physical ruler variant is being represented and distinguishes adjacent measuring tools.
The name alone does not establish the physical sense, measuring mechanism or scale interpretation.
Graduated tool identity
Identifies the combination of a linear body and a distance scale.
Ruler recognition
Record the observable features supporting classification as a graduated ruler.
- Does the object carry graduations that represent linear distances along its body? definition
- What distinguishes it from an ungraduated straightedge, retractable tape or contact measuring instrument? boundary
Variant and scale boundary
Separates ordinary ruler variants from tools requiring additional mechanisms or conversion semantics.
Construction and reading mode
Record whether construction and scale interpretation fit this model or require a neighbouring model.
- Is the body rigid, flexible or articulated, and does its construction introduce a joint or extension mechanism? definition
- Does each scale read physical distance directly, or does it require a drawing-scale conversion? boundary
Graduations and reading Describes how the ruler encodes distance and how its readings are interpreted.
Units, division spacing and zero placement determine what a ruler reading means.
Scale encoding
Records the units, range and subdivisions of each independently readable scale.
Units, range and divisions
Describe each scale separately where opposite edges or faces use different units or divisions.
- What units, numbered range and smallest division does each scale provide? measurement
- Which printed labels or documentation establish how unlabelled subdivisions should be interpreted? provenance
Origin and endpoint reading
Determines where measurement starts and how endpoint positions become a distance.
Zero and difference reading
Record the relationship between the physical end, zero mark and any alternative starting graduation.
- Does zero coincide with the physical end, and what offset exists if it does not? measurement
- If zero is damaged or inaccessible, which intact starting mark can be used and subtracted from the endpoint reading? action
- How should the eye or camera be positioned to limit ambiguity caused by separation between the scale and target? action
Body, edge and placement Connects the ruler's physical form to measurement alignment and line guidance.
A readable scale does not establish that the body can lie correctly or that an edge can guide a straight mark.
Measuring placement
Assesses how the ruler meets and aligns with the measured surface.
Contact and alignment
Record the body properties and placement conditions affecting the intended distance measurement.
- What body dimensions, flexibility and transparency affect placement and endpoint visibility? measurement
- Can the scale align with the intended measurement direction without bowing, slipping or bridging an obstruction? action
- Is the requested distance a straight span or a path along a curved surface? boundary
Straight-line guidance
Assesses a particular edge as a guide for a marking tool.
Usable guiding edge
Identify the edge and usable span for drawing or marking a straight line.
- Which edge is intended for guidance, and is it sufficiently straight and free of nicks over the required span? measurement
- How should the ruler be held and the marking tool positioned to prevent slipping or an unwanted offset? action
Measurement confidence and serviceability Supports decisions about whether the ruler remains suitable for a particular task.
Fine marks, intact appearance and a familiar material do not establish the accuracy of a measurement.
Accuracy evidence
Relates documented or measured performance to the task's required tolerance.
Supported measurement capability
Keep graduation interval distinct from verified scale error and uncertainty in use.
- What specification or comparison evidence supports the ruler's accuracy over the intended measurement interval? provenance
- What error or uncertainty is supported under the recorded conditions, and does it meet the task's tolerance? measurement
- Which stated environmental or support conditions must hold for that evidence to apply? boundary
Damage and continued use
Connects observed wear or deformation to allowed measurement and marking actions.
Usable regions and retirement
Assess scale readability, end wear and edge damage separately before deciding on continued use.
- Which graduations, physical ends or guiding-edge segments are worn, obscured, bent or otherwise damaged? measurement
- Can an intact region support the task with a documented method, or is replacement or further verification needed? action
- What cleaning or storage instructions apply to the actual body material and graduation method? provenance
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The sense is inferred from PHY.OBJ because no definition was recorded.
- Typical dimensions and graduations describe common products, not required specifications; graduation spacing does not establish measurement accuracy.
- Applicable dimensional tolerances, calibration requirements and legal-metrology rules need checking for the particular ruler type and intended use.
- Which of these check these first hold for the sense of ruler this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Rigid school or office ruler
- Steel rule
- Folding rule
- Flexible ruler
- Architect's scale ruler
- Engineer's scale ruler
- Which of these kinds and varieties hold for the sense of ruler this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Measuring short lengths and distances on objects or drawings
- Drawing straight lines and marking measured intervals
- Laying out dimensions for fabrication and craft work
- Reading scaled dimensions from architectural or engineering drawings
- Which of these real-world use hold for the sense of ruler this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Measuring length of common school and office rulers - 150-300 - mm
- Smallest graduation on common metric rulers - 0.5-1 - mm
- Smallest graduation on common inch rulers - 1/16-1/8 - in
- Which of these typical measurements hold for the sense of ruler this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Worn or illegible graduations cause reading errors.
- Bent, warped or damaged edges compromise alignment and straight-line guidance.
- Parallax and failure to align the scale's zero mark with the measurement origin introduce errors.
- Temperature changes can alter the ruler's length and matter in precision work.
- Using a ruler to guide a blade can expose fingers to cuts; an unsuitable edge may be damaged or let the blade slip.
- Which of these failure modes and hazards hold for the sense of ruler this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Metric graduations predominate in many countries; inch and dual-unit rulers are common in the United States.
- Architectural scale rulers use scale conventions associated with local drawing practice, including metric ratios and fractional inches per foot.
- Which of these regional variation hold for the sense of ruler this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Straightedge - A straightedge provides a reference edge for drawing or checking straightness but need not carry a measuring scale.
- Tape measure - A tape measure uses a flexible graduated strip that coils or retracts and commonly measures longer distances.
- Caliper - A caliper locates surfaces with jaws or other contacts rather than relying solely on visual alignment with a ruler's scale.
- Measuring scale - A measuring scale is the graduated reference itself and may be incorporated into instruments other than rulers.
- Political ruler - This is a person exercising governing authority; the PHY.OBJ entry is interpreted as the measuring tool.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of ruler this model covers, and on what evidence? provenance
What the second pass must settle
- Does the registry intend this entry to include folding rules and dedicated scale rulers, or are these owned by neighbouring entries?
- Which ruler-specific standards and issuing bodies apply to the intended variants and jurisdictions, and what evidence establishes applicability?
- What accuracy claims, reference conditions and verification methods are documented for representative ruler constructions?
- Which material-specific cleaning, storage and damage criteria can be supported by manufacturer guidance?
- What typical graduated ranges and division intervals should the model recognise once representative products have been researched?