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Research draft

barometer

vr.tr.barometer · PHY.OBJ

Enable an AI agent to recognise a barometer, assess whether its atmospheric-pressure readings are usable, and decide how it may be read, positioned, checked or serviced.

Thing Registry Physical world and living systems

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.

Researched by: Codex + Grok

Purpose and description

Enable an AI agent to recognise a barometer, assess whether its atmospheric-pressure readings are usable, and decide how it may be read, positioned, checked or serviced.

A barometer is a scientific instrument that measures atmospheric pressure, typically to forecast weather, determine altitude, or provide a pressure reference for calibration and process control.

It can be Read and record atmospheric pressure with its unit, time and reference basis.; Inspect placement and the ambient-pressure path for conditions that undermine the reading.; Compare readings with a suitable reference under compatible conditions.; Calculate pressure change from observations with consistent reference settings.; Apply documented configuration or calibration adjustments when authorised and supported by evidence.; Flag unreliable readings and route damaged or unsuitable instruments for appropriate servicing..

Distinguishing features

Its intended measured quantity is atmospheric pressure; a device intended to measure pressure inside a process line belongs to a neighbouring pressure-instrument model.

Its sensing arrangement measures ambient pressure against an absolute reference, rather than merely comparing two external pressure ports.

A pressure-derived altitude display alone identifies an altimeter function; establish whether atmospheric-pressure indication is also an intended function before treating the device as a barometer.

A weather-labelled dial qualifies through a pressure-sensitive mechanism; labels such as rain or fair do not themselves establish pressure measurement.

A remotely displayed pressure value does not establish a local barometer; identify the physical sensor and its relationship to the display.

Scope

+ Instrument identity and atmospheric-pressure sensing mechanism

+ Pressure readings, units, timestamps and reference basis

+ Exposure to ambient air and installation conditions

+ Calibration, compensation, faults and reading uncertainty

+ Instrument-specific reading, adjustment and servicing constraints

- Weather systems, forecasts and meteorological observations beyond this instrument

- Altitude determination and navigation performed using pressure

- General-purpose pressure gauges for vessels, pipes or process systems

- The complete weather station or building containing the barometer

- Regional pressure datasets and their aggregation services

Characteristics

Sensing mechanism
Liquid-column, mechanical aneroid, electronic absolute-pressure sensor, other documented mechanism, unknown Determines how pressure becomes an indication and which reading or handling constraints apply.
Atmospheric pressure indication
Recorded value and displayed unit, such as Pa, hPa, kPa, mbar, mmHg or inHg Preserves the actual observation and prevents errors from assumed units.
Pressure reference basis
Local absolute pressure, sea-level-reduced pressure, other documented adjustment, unknown Determines whether readings can be compared directly with another instrument or report.
Observation time
Timestamp with time zone; acquisition interval where applicable Distinguishes current readings from stale indications and supports pressure-change calculations.
Pressure range
Lower and upper pressure limits with unit and documented source Establishes whether a reading falls within the instrument's specified operating range.
Resolution and measurement uncertainty
Scale division or digital increment and separately documented uncertainty or accuracy specification, in pressure units Prevents displayed precision from being mistaken for measurement reliability.
Ambient-pressure connection
Sensing port or exposed element linked to the sampled air volume Establishes which atmosphere the reading represents and whether the pressure path is obstructed.
Installation elevation
Metres relative to a named vertical datum, with uncertainty where known Supports interpretation of local pressure and assessment of configured elevation corrections.
Correction configuration
Enabled corrections, parameter values, method or firmware version, unknown Separates sensed pressure from values transformed by instrument settings.
Calibration evidence
Link to calibration or comparison record, reference instrument, date and applicable conditions Provides evidence for judging bias and whether an adjustment is justified.
Reading validity
Unchecked, usable under recorded conditions, suspect, invalid, unavailable Controls whether an agent may rely on the reading or must request a check.
Contained working material
Documented liquid or other relevant material; absent, unidentified or unknown Determines instrument-specific handling and service requirements without assuming that every barometer contains mercury.

Also called

aneroidmercury barometermicrobarometer

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.barometer

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 9 findings · 17 questions.

Pressure-sensing identity Establishes what senses atmospheric pressure and how that sensing produces the observed indication.

An agent must distinguish a barometer from a pressure gauge, altimeter or display that merely repeats another sensor's output.

Sensing principle

Identifies the pressure-sensitive mechanism and its reference.

Atmospheric-pressure function

Record evidence that the instrument is intended to measure atmospheric pressure and identify its sensing mechanism.

  1. What documentation or physical features establish that this instrument measures atmospheric pressure? definition
  2. What sensing mechanism and pressure reference does this instrument use? definition

Sensor and indication

Connects the physical sensor to the dial, column, screen or transmitted reading.

Reading origin

Identify the sensor responsible for each indication and separate pressure measurement from adjacent functions.

  1. Is this indication produced by an internal sensor or received from a separately identified instrument? provenance
  2. Which outputs indicate pressure, and which instead express altitude, weather labels or other derived quantities? boundary
Pressure reading and reference Preserves the observed pressure and the transformations needed to interpret it.

Identical displayed numbers may represent different pressure bases, while different units may represent the same pressure.

Observed indication

Captures what was actually read and when.

Pressure observation

Record the pressure value, unit, acquisition time and limits imposed by the indication.

  1. What pressure value and unit were indicated at the recorded observation time? measurement
  2. What scale division, display increment or acquisition interval limits interpretation of this observation? measurement

Reference and corrections

Explains whether the indication is local pressure or a corrected value.

Reported pressure basis

Record the pressure basis and any applied corrections without treating configuration changes as atmospheric changes.

  1. Does the indication represent local absolute pressure, sea-level-reduced pressure or another documented basis? definition
  2. Which elevation, temperature, offset or other correction settings affected this reading, and where are their methods documented? provenance
Atmospheric exposure and installation Connects the measurement to the air being sampled and the instrument's placement.

A functioning sensor can produce an unrepresentative reading when its pressure connection or installation is unsuitable.

Sampled air

Identifies the air volume communicating with the sensing element.

Ambient-pressure path

Record the pressure path and evidence that it represents the intended atmosphere.

  1. Which room, enclosure or outdoor air volume communicates with the pressure-sensitive element? boundary
  2. What evidence indicates an unobstructed pressure path or possible influence from enclosure pressure, ventilation or airflow? measurement

Placement conditions

Records installation details that affect this instrument's interpretation or operation.

Installation suitability

Assess elevation, orientation and environmental conditions against requirements for the identified instrument.

  1. What are the instrument's elevation, orientation and relevant environmental conditions? measurement
  2. Does its documentation require repositioning, levelling or an equilibration period before readings are used? action
Measurement trust and intervention Determines whether readings are credible and which checks or interventions are appropriate.

An agent needs evidence to distinguish atmospheric change from instrument error and to avoid unsupported adjustments.

Calibration and comparison

Establishes evidence for measurement quality using compatible reference observations.

Pressure agreement

Record calibration evidence or comparison results with matching pressure bases and relevant conditions.

  1. What calibration or reference-comparison record supports the instrument's current measurement quality? provenance
  2. After accounting for time, elevation and pressure basis, what discrepancy and uncertainty remain? measurement

Faults and permitted actions

Links observed defects and instrument construction to reading restrictions and servicing decisions.

Reading validity and service

Record symptoms such as a stuck indication, interrupted liquid column, blocked port or electronic fault, and identify documented responses.

  1. Which observed symptoms make this reading suspect, invalid or unavailable? measurement
  2. Which checks, adjustments or servicing actions are documented and authorised for this mechanism and its contained materials? action
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.

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

  • mercury barometer (Torricelli / cistern and Fortin)
  • aneroid barometer (evacuated capsule / Bourdon)
  • electronic / MEMS digital barometer
  • barograph (recording barometer)
  • marine / ship barometer
  • altimeter-barometer (pressure altimeter)
  • water / glycerine barometer (low-density liquid column)
  1. Which of these kinds and varieties hold for the sense of barometer this model covers, and on what evidence? provenance

Sources

  1. Research in progress - Initial draft only; will be replaced after lookups.

What the second pass must settle

  • Does the registry intend this entry to include embedded barometric sensors and remote sensor assemblies, or only complete instruments?
  • Which authoritative documentation should define reading and correction procedures for each supported mechanism?
  • What measurement uncertainty and calibration evidence are sufficient for each intended use?
  • How should the model distinguish factory compensation, user display offsets and sea-level reduction when an instrument exposes only a single adjustment?
  • Which mechanism-specific handling and service requirements must be represented, particularly for instruments containing an identified liquid?