incandescent light bulb
Enable an AI agent to recognise an incandescent light bulb, assess its condition and suitability for an intended use, and determine whether it can be installed, operated, handled or replaced.
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 an incandescent light bulb, assess its condition and suitability for an intended use, and determine whether it can be installed, operated, handled or replaced.
An incandescent light bulb is an electric lamp in which a resistive filament, almost always drawn tungsten in modern practice, is heated to incandescence by current inside a glass envelope that is evacuated or filled with inert or halogen-bearing gas so the filament does not oxidize.
It can be Identify an incandescent bulb and distinguish its construction variant from similar-looking replacement technologies.; Compare its base, supply rating, dimensions and power against a proposed socket and luminaire.; Select an operating or dimming setting supported by the bulb and connected equipment.; Inspect filament, envelope and contacts to assess whether further testing or replacement is appropriate.; Determine when and how the bulb may be removed or installed using its thermal condition and documented handling requirements.; Choose a replacement that preserves the required light output, distribution and application constraints..
Distinguishing features
Determine whether useful light comes from an electrically heated filament; a filament-shaped LED assembly does not satisfy this test.
Distinguish thermal filament emission from a gas discharge or phosphor-based source using reliable product identification or construction evidence, rather than warm colour alone.
Check for a sealed envelope enclosing a filament and its supports; envelope shape and screw-base appearance alone cannot establish incandescent identity.
Treat a halogen capsule as a possible incandescent variant, including when it sits inside an outer bulb; establish the variant from product documentation or adequate construction evidence.
Scope
+ Filament-based light production and identification of incandescent variants
+ Envelope, internal atmosphere, filament supports and base construction
+ Rated electrical operation and compatibility requirements
+ Light output, distribution, colour appearance and dimming behaviour
+ Bulb condition, failure evidence, handling constraints and replacement suitability
- Luminaire housing, reflector design, ventilation and protective guards
- Socket construction, fixed wiring and circuit protection
- Dimmer or lighting controller internals
- Room illumination requirements and lighting installation design
- LED, fluorescent and discharge lamps that imitate incandescent bulb shapes
- Waste collection infrastructure and jurisdictional disposal rules
Characteristics
- Incandescent variant
- non-halogen incandescent | halogen incandescent | unresolved The variant affects envelope construction, handling requirements and operating constraints.
- Rated supply
- V, with documented AC/DC applicability A mechanically fitting bulb may still be electrically unsuitable.
- Rated input power
- W at the stated rated supply Power determines electrical demand and informs comparison with fixture limits.
- Base designation
- documented base code, contact arrangement and keying The base controls mechanical seating and electrical contact compatibility.
- Envelope dimensions
- mm for overall length, maximum diameter and relevant clearance dimensions A bulb must fit without contacting surrounding parts or violating specified clearances.
- Envelope treatment
- clear | frosted | coloured | reflective | other documented treatment | unknown Treatment affects visible filament glare, light distribution and application suitability.
- Luminous flux
- lm, with supply and measurement or rating conditions Electrical wattage alone does not establish delivered light output.
- Colour appearance
- correlated colour temperature in K where applicable, with operating conditions Appearance can change with operating level and may determine replacement suitability.
- Envelope and base integrity
- intact | cracked | broken | loose base | damaged contacts | unassessed; multiple defects may coexist Physical defects can rule out installation or ordinary handling.
- Filament condition
- apparently intact | electrically continuous | open circuit | deformed | unresolved Visual inspection and continuity evidence answer different questions about serviceability.
- Thermal condition
- energised | recently operated | measured temperature available | sufficiently cooled for specified handling | unknown Switching off does not establish that the bulb is ready to handle.
- Intended fixture compatibility
- target socket or luminaire, with matched requirements and unresolved constraints Installation suitability depends on electrical, dimensional, thermal and application compatibility together.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Incandescent identity Establishes the light-producing mechanism and the construction variant of the bulb.
Shape, base and warm light are shared with other technologies and cannot establish identity.
Emission mechanism
Separates a heated filament from visually similar light sources.
Heated filament evidence
Records evidence that a current-heated filament produces the useful light, including limits imposed by an opaque envelope.
- What construction evidence or product documentation establishes that light is produced by an electrically heated filament? definition
- Could the visible filament-like elements instead be LED assemblies, and what evidence resolves that ambiguity? boundary
Envelope and variant
Identifies conventional and halogen construction without guessing concealed materials.
Sealed light-source construction
Records the envelope or nested capsule arrangement and documented filament material and internal atmosphere.
- Does the filament sit directly inside the outer envelope or inside a separate capsule? definition
- Which markings or manufacturer records establish the variant, filament material and internal atmosphere, and which remain unknown? provenance
Electrical and socket fit Captures the conditions under which the bulb can connect and operate as intended.
A matching base does not guarantee a suitable supply, power allowance or control arrangement.
Rated electrical operation
Establishes supply and power requirements for the specific bulb.
Supply and load match
Relates the bulb's documented electrical ratings to the proposed supply and fixture allowance.
- What voltage and input power are marked or documented for this bulb, and what supply conditions qualify those ratings? measurement
- Does the proposed supply and luminaire power allowance support operating this bulb? action
Base and control interface
Addresses contact fit and the equipment used to switch or dim the filament.
Installation and dimming compatibility
Records the base and contact requirements separately from compatibility with a dimmer, transformer or other supply equipment.
- What base designation, contact arrangement and seating requirements must the target socket satisfy? definition
- What evidence supports use with the proposed dimmer or supply equipment, including any minimum load or operating restrictions? action
Light output and appearance Describes the useful light delivered by the filament and modified by the bulb envelope.
Replacing a bulb by wattage or shape alone can change brightness, glare, colour or beam behaviour.
Output at operating level
Relates brightness and colour appearance to stated operating conditions.
Flux and colour evidence
Keeps rated output distinct from observed output at a particular supply or dimming setting.
- What luminous flux and colour appearance are documented or measured, and at what supply or dimming level? measurement
- At the intended operating level, does this bulb meet the required brightness and colour appearance? action
Envelope optics
Captures how bulb shape, coatings and filament position affect emitted light.
Distribution and filament visibility
Records diffusion, coloration, integral reflection and filament visibility attributable to the bulb itself.
- How do the envelope treatment and filament position affect filament visibility and light distribution? definition
- Which observed beam or glare properties belong to the bulb, and which are produced by the surrounding luminaire? boundary
Heat and envelope constraints Captures thermal handling and installation conditions associated with the operating filament and its enclosure.
Electrical compatibility alone cannot establish safe handling or suitability for an enclosed or specialised fixture.
Thermal handling
Determines whether present temperature and supply state permit the intended handling action.
Handling readiness
Records recent operation, isolation evidence and the basis for judging the bulb sufficiently cool to handle.
- What evidence establishes the bulb's present thermal condition following its most recent operation? measurement
- What isolation, cooling and variant-specific handling steps are required before removing or installing it? action
Application restrictions
Captures documented limits for enclosure, orientation, exposure and protective shielding.
Permitted operating environment
Records restrictions that belong to this bulb variant and compares them with the intended installation.
- What manufacturer instructions specify permitted orientation, enclosure, shielding or environmental exposure? provenance
- Does the intended installation satisfy those restrictions, including any requirements for an exposed halogen capsule? action
Condition and replacement Assesses degradation and failure while preserving uncertainty about causes outside the bulb.
A dark bulb is not proof of a failed filament, and nominal service life does not establish an individual bulb's remaining life.
Failure evidence
Separates visible damage, filament continuity and observed lighting behaviour.
Bulb serviceability
Records cracks, blackening, filament disruption, loose components and contact damage without treating a single observation as a complete diagnosis.
- What envelope, filament, support, base or contact defects are visible, and what suitably isolated test evidence is available? measurement
- Does the evidence locate the fault in the bulb, or could the socket, supply or controller explain the observed failure? boundary
Service history and substitution
Supports replacement decisions using known use history and the requirements of the intended application.
Replacement decision
Distinguishes documented life ratings from individual service history and identifies requirements a replacement must preserve.
- What operating hours, switching history and unusual operating conditions are known, and how were they recorded? provenance
- Which electrical, dimensional, optical and application requirements must a replacement satisfy before it can be accepted? 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.
- General lighting service (GLS) A/PS pear-shaped tungsten-filament lamps
- Tungsten-halogen lamps (mains-voltage and extra-low-voltage capsules)
- Reflector and directional lamps (R, BR, PAR, MR)
- Decorative and special-shape lamps (candelabra, globe, tubular)
- Rough-service, vibration-resistant, and appliance/oven lamps
- Automotive, traffic, and signal filament lamps
- Photographic, projection, and studio lamps (high filament temperature, short life)
- Infrared heat lamps
- Which of these kinds and varieties hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q47616 - Item labelled incandescent light bulb / incandescent lamp.
- IEC 60050 IEV - 845-27-011 - Term 'incandescent lamp'; numbered 845-07-04 in the 1987 edition.
- ICS - 29.140.20 - Incandescent lamps.
- HS / Harmonized System - 8539.21 | 8539.22 | 8539.29 - 8539.21 tungsten-halogen; 8539.22 other filament lamps ≤200 W and >100 V; 8539.29 other filament lamps.
- CPC / IPC - H01K - Electric incandescent lamps.
- IEC 60061 cap designation - E12 | E14 | E26 | E27 | B15d | B22d | G4 | GU5.3 | GU10 - Mechanical/electrical cap, not a unique product code.
- IEC 60887 / ANSI C79.1 bulb shape - A19 | A60 | PS | PAR38 | R80 | MR16 | T | CA - Letter is shape, number is maximum diameter in eighths of an inch (ANSI) or millimetres (IEC).
- Which of these identifiers and schemes hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- IEC 60050-845 International Electrotechnical Vocabulary - Lighting (IEC)
- IEC 60064 tungsten-filament GLS performance requirements (IEC)
- IEC 60432-1 incandescent lamp safety specifications, tungsten filament for domestic and similar use (IEC)
- IEC 60061 lamp caps and holders with gauges (IEC)
- IEC 60630 maximum lamp outlines for incandescent lamps (IEC)
- IEC 60887 / IEC TR 60887 glass bulb designation system for lamps (IEC)
- ANSI C79.1 nomenclature for glass bulbs intended for lamps (ANSI)
- Energy Independence and Security Act of 2007 and 10 CFR 430 (U.S. Congress / DOE): general-service lamps must meet at least 45 lm/W; a stricter GSL efficacy rule takes effect 25 July 2028
- EU ecodesign rules for light sources (European Commission): GLS phased out; halogen later restricted by successive stages
- Greenhouse and Energy Minimum Standards (Incandescent Lamps for General Lighting Services) Determination 2016 and AS/NZS 4934 (Australia)
- Which of these standards and regulation hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Still found in older household ceiling roses, table lamps, and ovens, though new GLS sales are blocked or restricted in the EU, United States, Australia, Canada and several other markets.
- Sold as 'vintage' or carbon-look decorative lamps in exposed fixtures where the filament itself is the visual object.
- Used where electronics fail: high-temperature appliance compartments, vibration-prone industrial fittings, and some extra-low-voltage halogen display lighting.
- Automotive stop, indicator, and some headlamp bulbs remain filament types in many vehicles.
- Photographic, projector, and studio lamps exploit a near-black-body spectrum and high filament temperature at the cost of short life.
- Quartz-halogen infrared lamps are used as heat sources (paint curing, space heating, incubators) rather than for illumination.
- Which of these real-world use hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- rated electrical power (GLS) - 25-200 - W
- luminous flux (household GLS) - about 400-1700 - lm
- luminous efficacy - 10-18 GLS; 16-24 halogen - lm/W
- rated average life (GLS in product standards) - 1000 (common rating; 750-2000 in trade) - h
- filament temperature - 2000-3300 - K
- correlated colour temperature - about 2700-3200 - K
- rated supply voltage - 12/24 (ELV); 100-130; 220-250 - V
- soft-glass GLS envelope surface temperature - 200-260 - °C
- Which of these typical measurements hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Normal end of life is tungsten evaporation until the filament necks and opens; evaporated metal blackens the envelope and cuts light output.
- A leak lets oxygen reach the hot filament; the wire burns away at once and deposits tungsten oxides/nitrides on the glass.
- Cold-filament inrush current is several times running current and can blow weak fuses or weld switch contacts.
- Overvoltage shortens life sharply (life scales steeply with voltage); undervoltage dimms and reddens the light.
- Mechanical shock or vibration breaks a hot, ductile-then-brittle coiled filament, the reason rough-service lamps exist.
- Envelope temperatures of 200 °C and above can ignite adjacent combustibles or overheat a luminaire not rated for the wattage.
- Bare quartz-halogen capsules emit ultraviolet if the outer envelope is missing or broken, and the inner capsule can rupture.
- Broken glass and hot fragments are a handling hazard at failure.
- Which of these failure modes and hazards hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Household voltage splits the product: 120 V A19/E26 lamps (North America) versus 230 V A60/E27 or B22d lamps (Europe, UK, Australia, much of Asia); the higher-voltage filament is thinner and slightly less efficacious.
- UK, Australia, New Zealand and India still use B22d bayonet caps alongside Edison screw; North America uses E26 medium screw as the default.
- Australian English commonly says 'light globe'; German 'Glühbirne'/'Glühlampe'; in parts of Central Europe older tungsten GLS lamps are still called Tungsram bulbs after the 1904 patent holders.
- Shape numbering differs: ANSI A19 is the same physical family as IEC A60 (diameter in eighths of an inch versus millimetres).
- Phase-out is not uniform: the EU, United States, Australia, Canada, Russia, Brazil and Argentina have efficacy floors that exclude ordinary GLS, while specialty, oven, rough-service, and some extra-low-voltage halogen types remain legal longer.
- Which of these regional variation hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- LED retrofit lamp - Same cap and often the same A-shape, but light comes from a semiconductor package and driver, not a glowing filament; envelope stays relatively cool and efficacy is typically >80 lm/W versus ~10-18 lm/W.
- compact fluorescent lamp (CFL) - A mercury discharge tube with phosphor and a ballast in the cap; it has a warm-up delay and a line spectrum, not a continuous black-body filament spectrum.
- tungsten-halogen lamp - A subclass of incandescent, not a different physics: a halogen regenerative cycle in a compact high-temperature envelope. Separate it from GLS by the halogen fill, quartz or hard-glass capsule, and typically higher efficacy and envelope temperature.
- high-intensity discharge (HID) lamp - Light comes from an arc in a metal-vapour or metal-halide tube that needs a ballast; there is no continuous tungsten filament.
- carbon-arc lamp - An open or enclosed arc between carbon electrodes, historically used for large-area lighting; not a sealed, current-heated wire in a bulb.
- Nernst lamp - Incandescence of a ceramic globar in air, not a metal filament in vacuum or inert gas.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of incandescent light bulb this model covers, and on what evidence? provenance
Sources
- IEV 845-27-011 incandescent lamp - IEC International Electrotechnical Vocabulary definition and the IEV number used as an identifier.
- Incandescent light bulb - Construction, filament temperature, efficacy figures, gas fill, failure chemistry, shape codes, colour rendering, and phase-out context.
- incandescent light bulb (Q47616) - Wikidata item, aliases, IEV cross-reference, and subclass relation to light bulb.
- IEC 60064 Tungsten filament lamps for domestic and similar general lighting purposes - Performance requirements - GLS scope (wattage, voltage, A/PS shapes, caps B22d/E26/E27) and linkage to IEC 60432-1 safety and IEC 60630 outlines.
- Requiem for the Incandescent Lightbulb - Drawn-tungsten filament history, inert-gas fill versus vacuum, and halogen as a later incandescent variant.
- Greenhouse and Energy Minimum Standards (Incandescent Lamps for General Lighting Services) Determination 2016 - Legal definitions of incandescent, tungsten filament, and tungsten halogen lamps, and Australian product classes.
- Energy Conservation Program: Energy Conservation Standards for General Service Lamps - U.S. DOE GSL/GSIL efficacy rules, the 45 lm/W backstop, and the 2028 amended standards.
- Light Sources - EU practice of treating GLS and halogen (HL) as distinct incandescent groups and typical efficacy bands.
What the second pass must settle
- Does the registry intend this entry to include all halogen incandescent lamps, miniature indicator bulbs and specialised infrared lamps, or are some owned by neighbouring entries?
- Which authoritative base and envelope designation references should agents use to resolve regional markings and visually similar fittings?
- What manufacturer evidence is available for variant-specific cooling, handling, shielding and enclosure requirements?
- Which inspection and isolated test procedures provide sufficient evidence for serviceability without overstating what visual inspection or continuity can establish?
- How should application-specific replacement requirements be obtained when the bulb markings, original packaging or luminaire instructions are missing?