Thermal Measurements
Authors:
MArk Anthony Higgins - Sky Recursive Ai
MArk Anthony Higgins - Sky Recursive Ai
© Mark Anthony Higgins 11 October 2025
Revised Date: July 6th 2026
Revised Date: July 6th 2026
# Thermal Measurements Ontology — Flow Algebra
URL: https://kirethresearch.org/booksai-core/ontologies/mathematical-ontologies/measurement-units-ontologies/thermal-measurements.html
FLOW ThermalMeasurementsOntology {
DOMAIN:
Mathematical Ontologies
-> Measurement & Units Ontologies
-> Thermal Measurements Ontology
PURPOSE:
Represent the semantic and mathematical structure of thermal measurement quantities, units, material properties, energy-transfer mechanisms, thermodynamic state variables, measurement methods, reference scales, uncertainty, dimensional relationships, and transformations required for consistent AI interpretation and reasoning across thermal and thermodynamic domains.
SCOPE {
temperature
temperature_difference
heat
thermal_energy
heat_capacity
specific_heat_capacity
thermal_conductivity
thermal_resistance
heat_flux
heat_transfer_coefficient
thermal_expansion
phase_change
entropy
thermodynamic_state
thermal_measurement_instruments
uncertainty_and_calibration
}
ENTITY Temperature {
TYPE: SIBaseQuantity
SYMBOL: T
DIMENSION: Theta
SI_UNIT: kelvin
SI_SYMBOL: K
PROPERTIES:
scalar_quantity
state_variable
may_vary_with_position
may_vary_with_time
requires_scale_definition
}
ENTITY TemperatureDifference {
TYPE: ThermalDifferenceQuantity
SYMBOL: delta_T
DIMENSION: Theta
SI_UNIT: kelvin
SI_SYMBOL: K
RELATION:
delta_T = T_2 - T_1
}
ENTITY Heat {
TYPE: EnergyTransferQuantity
SYMBOL: Q
DIMENSION: M*L^2*T^-2
SI_UNIT: joule
SI_SYMBOL: J
DEFINITION:
heat := energy_transfer_due_to_temperature_difference
RULE:
heat_is_not_a_stored_state_property
}
ENTITY HeatCapacity {
TYPE: DerivedThermalQuantity
SYMBOL: C
DIMENSION: M*L^2*T^-2*Theta^-1
SI_UNIT: joule_per_kelvin
SI_SYMBOL: J/K
SIMPLE_RELATION:
C = delta_Q/delta_T
UNDER applicable_process_context
}
ENTITY SpecificHeatCapacity {
TYPE: MaterialProperty
SYMBOL: c
DIMENSION: L^2*T^-2*Theta^-1
SI_UNIT: joule_per_kilogram_kelvin
SI_SYMBOL: J/(kg*K)
SIMPLE_SENSIBLE_HEAT:
Q = m*c*delta_T
UNDER applicable_constant_c_context
}
ENTITY ThermalConductivity {
TYPE: MaterialProperty
SYMBOL: k
DIMENSION: M*L*T^-3*Theta^-1
SI_UNIT: watt_per_metre_kelvin
SI_SYMBOL: W/(m*K)
}
ENTITY HeatFlux {
TYPE: VectorOrNormalSurfaceFluxQuantity
SYMBOL: q_double_prime
DIMENSION: M*T^-3
SI_UNIT: watt_per_square_metre
SI_SYMBOL: W/m^2
}
ENTITY HeatTransferCoefficient {
TYPE: EffectiveBoundaryProperty
SYMBOL: h
SI_UNIT: watt_per_square_metre_kelvin
SI_SYMBOL: W/(m^2*K)
}
ENTITY ThermalResistance {
TYPE: DerivedThermalQuantity
SYMBOL: R_th
SI_UNIT: kelvin_per_watt
SI_SYMBOL: K/W
RELATION:
R_th = delta_T / heat_transfer_rate
WHEN heat_transfer_rate != 0
}
ENTITY Entropy {
TYPE: ThermodynamicStateQuantity
SYMBOL: S
SI_UNIT: joule_per_kelvin
SI_SYMBOL: J/K
}
UNIT_SYSTEM {
TEMPERATURE_SI:
kelvin
symbol: K
COMMON_TEMPERATURE_SCALES:
degree_Celsius
degree_Fahrenheit
ENERGY:
joule
POWER:
watt
RULE:
absolute_temperature_and_temperature_difference
MUST preserve_scale_semantics
CELSIUS_KELVIN:
T_K = T_C + 273.15
TEMPERATURE_DIFFERENCE:
delta_1_K = delta_1_degree_Celsius
RULE:
Celsius_offset_applies_to_absolute_reading
NOT directly_to_temperature_difference
}
TEMPERATURE_MODEL {
absolute_temperature:
thermodynamic_temperature_on_kelvin_scale
Celsius_temperature:
offset_scale_relative_to_kelvin
Fahrenheit_temperature:
affine_scale_with_different_interval_size
absolute_zero:
0 K
CONSTRAINT:
thermodynamic_absolute_temperature >= 0 K
under_standard_equilibrium_thermodynamic_interpretation
}
HEAT_ENERGY_DISTINCTION_MODEL {
internal_energy:
state_function
heat:
energy_transfer_across_system_boundary_due_to_temperature_difference
work:
other_energy_transfer_mode
FIRST_LAW:
delta_U = Q - W_by_system
UNDER stated_sign_convention
RULE:
heat MUST_NOT be treated_as_energy_contained_in_body
without clarifying informal_usage
}
SENSIBLE_HEAT_MODEL {
CONSTANT_SPECIFIC_HEAT_APPROXIMATION:
Q = m*c*delta_T
GENERAL:
Q = m*integral(c(T) dT)
CONDITIONS:
no_phase_change
applicable_process_and_material_model
RULE:
specific_heat MAY depend_on temperature_pressure_and_process_constraint
}
LATENT_HEAT_MODEL {
PHASE_CHANGE:
Q = m*L_phase
examples:
latent_heat_of_fusion
latent_heat_of_vaporisation
latent_heat_of_sublimation
CONDITION:
phase_transition_context_defined
RULE:
temperature_may_remain_approximately_constant_during_phase_change
while_energy_is_transferred
}
CONDUCTION_MODEL {
FOURIER_LAW:
q_vector = -k*gradient(T)
ONE_DIMENSIONAL_STEADY_PLANE_WALL:
heat_transfer_rate = k*A*(T_hot - T_cold)/L
THERMAL_RESISTANCE:
R_cond = L/(k*A)
CONDITIONS:
continuum_model
applicable_conductivity
defined_geometry
RULE:
negative_sign indicates_heat_flow_toward_decreasing_temperature
}
CONVECTION_MODEL {
NEWTON_COOLING:
heat_transfer_rate = h*A*(T_surface - T_fluid)
HEAT_FLUX:
q_double_prime = h*(T_surface - T_fluid)
RULE:
h is_effective_context_dependent_coefficient
not_intrinsic_material_constant
}
RADIATION_MODEL {
STEFAN_BOLTZMANN_SURFACE:
heat_transfer_rate =
epsilon*sigma_SB*A*(T_surface^4 - T_surroundings^4)
PARAMETERS:
epsilon = emissivity
sigma_SB = Stefan_Boltzmann_constant
CONDITIONS:
absolute_temperature_in_kelvin
applicable_radiative_exchange_model
RULE:
Celsius_or_Fahrenheit MUST_NOT be inserted_directly_into_T_fourth_power_relation
}
THERMAL_EXPANSION_MODEL {
LINEAR:
delta_L = alpha*L_0*delta_T
VOLUMETRIC:
delta_V = beta*V_0*delta_T
PARAMETERS:
alpha = linear_thermal_expansion_coefficient
beta = volumetric_thermal_expansion_coefficient
CONDITIONS:
applicable_temperature_range
material_state_defined
}
THERMAL_DIFFUSIVITY_MODEL {
ENTITY ThermalDiffusivity {
SYMBOL: alpha_th
SI_UNIT: square_metre_per_second
SI_SYMBOL: m^2/s
RELATION:
alpha_th = k/(rho*c_p)
}
INTERPRETATION:
rate_at_which_temperature_disturbances_diffuse_through_material
}
HEAT_TRANSFER_BALANCE_MODEL {
system_energy_balance:
accumulation =
heat_in - heat_out
+ work_or_other_energy_terms
+ generation
UNDER defined_sign_convention
steady_state:
accumulation = 0
RULE:
system_boundary_and_sign_convention MUST be explicit
}
ENTROPY_MODEL {
REVERSIBLE_TRANSFER:
dS = delta_Q_rev/T
CLAUSIUS_INEQUALITY:
entropy_generation >= 0
for_real_irreversible_processes
RULE:
entropy_change_and_heat_transfer
MUST_NOT be treated_as_semantically_equivalent
}
RELATIONSHIPS {
Temperature -> DRIVES -> HeatTransfer
TemperatureDifference -> DRIVING_POTENTIAL_FOR -> ThermalTransport
Heat -> TRANSFERS -> Energy
HeatCapacity -> RELATES -> HeatAndTemperatureChange
SpecificHeatCapacity -> MATERIAL_PROPERTY_FOR -> SensibleHeating
ThermalConductivity -> RELATES -> TemperatureGradientAndHeatFlux
HeatFlux -> REPRESENTS -> HeatTransferRatePerArea
HeatTransferCoefficient -> RELATES -> SurfaceTemperatureDifferenceAndConvectiveFlux
ThermalResistance -> RELATES -> TemperatureDifferenceAndHeatTransferRate
ThermalDiffusivity -> RELATES -> ConductivityDensityAndSpecificHeat
Entropy -> RELATES_TO -> ReversibleHeatTransferAndTemperature
}
SEMANTIC_EQUIVALENCE {
"temperature" ~= thermal_temperature WHEN thermal_context
"kelvin" ~= "K"
"degree Celsius" ~= "°C"
"heat flux" ~= heat_transfer_rate_per_unit_area
heat != temperature
heat != internal_energy
heat_capacity != specific_heat_capacity
thermal_conductivity != thermal_diffusivity
thermal_resistance != electrical_resistance
heat_flux != heat_transfer_rate
entropy != heat
}
CONSTRAINTS {
absolute_temperature_scale_must_be_identified = true
temperature_difference_and_absolute_temperature_must_be_distinguished = true
heat_is_energy_transfer_not_state_property = true
material_properties_require_applicable_conditions = true
phase_change_context_must_be_preserved = true
radiation_T_fourth_power_requires_absolute_temperature = true
heat_flux_and_total_heat_transfer_rate_are_not_semantically_equivalent = true
system_boundary_and_sign_convention_are_required_for_energy_balance = true
}
MEASUREMENT_MODEL {
TEMPERATURE_INSTRUMENTS:
thermocouple
resistance_temperature_detector
thermistor
liquid_in_glass_thermometer
infrared_thermometer
radiation_pyrometer
HEAT_AND_FLUX_INSTRUMENTS:
calorimeter
heat_flux_sensor
heat_flow_meter
thermal_conductivity_apparatus
RECORD:
quantity_type
numerical_value
unit
temperature_scale
absolute_or_difference
spatial_location
timestamp
material
phase
pressure_when_relevant
humidity_when_relevant
heat_transfer_mode
system_boundary
instrument
sensor_contact_or_noncontact
calibration_state
sampling_rate
response_time
uncertainty
UNCERTAINTY:
thermal_measurement = best_estimate +/- uncertainty
}
REASONING_RULES {
IF Celsius_temperature_known
THEN Kelvin_temperature = Celsius_temperature + 273.15
IF mass_specific_heat_and_temperature_change_known
AND constant_specific_heat_model_applies
THEN sensible_heat = mass*specific_heat*temperature_change
IF mass_and_latent_heat_known
AND applicable_phase_change_occurs
THEN phase_change_heat = mass*latent_heat
IF conductivity_and_temperature_gradient_known
THEN conductive_heat_flux = -conductivity*temperature_gradient
IF heat_transfer_coefficient_area_and_surface_fluid_temperature_difference_known
THEN convective_heat_transfer_rate =
coefficient*area*temperature_difference
IF emissivity_area_surface_and_surroundings_absolute_temperatures_known
THEN net_radiative_heat_transfer_rate =
emissivity*sigma_SB*area*(T_surface^4 - T_surroundings^4)
IF thermal_resistance_known AND temperature_difference_known
AND thermal_resistance != 0
THEN heat_transfer_rate = temperature_difference/thermal_resistance
IF conductivity_density_and_specific_heat_known
AND density != 0 AND specific_heat != 0
THEN thermal_diffusivity = conductivity/(density*specific_heat)
}
REFERENCE_MODEL {
temperature:
scale_and_reference_definition_required
temperature_difference:
interval_size_and_scale_required
material_properties:
temperature_pressure_phase_and_composition_may_be_required
heat_transfer:
system_boundary_direction_and_sign_convention_required
radiation:
absolute_temperature_required
RULE:
missing_reference_or_state_conditions
reduce_semantic_confidence
}
UNCERTAINTY_MODEL {
sources:
sensor_calibration
sensor_resolution
thermal_contact_resistance
radiation_error
conduction_along_sensor_leads
response_time
spatial_gradients
environmental fluctuations
emissivity_uncertainty
material_property_uncertainty
geometry_uncertainty
model_assumptions
PROPAGATION:
derived_thermal_quantity_uncertainty
<- measurement_material_geometry_and_model_uncertainties
}
CONFIDENCE {
quantity_definition_confidence: 1.00
SI_unit_confidence: 1.00
temperature_scale_confidence: 1.00
heat_transfer_relationship_confidence: 0.99
material_property_relationship_confidence: 0.98
measurement_context_confidence: 0.97
RULE:
confidence decreases when scale, state, material,
phase, pressure, system boundary, heat transfer mode,
calibration state or uncertainty is missing or ambiguous
}
VALIDATION {
CHECK dimensional_consistency
CHECK unit_consistency
CHECK temperature_scale
CHECK absolute_vs_difference_temperature
CHECK heat_vs_internal_energy_semantics
CHECK heat_capacity_vs_specific_heat_capacity
CHECK thermal_conductivity_vs_diffusivity
CHECK heat_flux_vs_total_heat_rate
CHECK material_temperature_pressure_phase_context
CHECK phase_change_conditions
CHECK absolute_temperature_for_radiation
CHECK system_boundary_and_sign_convention
CHECK instrument_calibration
CHECK uncertainty_representation_when_required
}
UPDATE_MODEL {
ON new_measurement:
identify_quantity_type
validate_unit
identify_temperature_scale_when_relevant
identify_absolute_or_difference_quantity
normalize_to_canonical_SI
preserve_original_value_and_unit
attach_spatial_location
attach_timestamp
identify_material_and_phase
attach_pressure_when_relevant
identify_heat_transfer_mode
attach_system_boundary_when_relevant
attach_uncertainty
update_thermal_state
ON material_state_change:
update_temperature
update_pressure
update_phase
update_material_properties
recompute_derived_quantities_when_model_available
preserve_previous_state
ON phase_change:
record_initial_phase
record_final_phase
record_latent_heat_transfer
preserve_transition_conditions
ON calibration_revision:
preserve_provenance
recompute_affected_measurements
update_confidence
ON semantic_revision:
preserve_previous_definition
record_revision
recompute_FLOW_HASH
}
AI_CONSUMPTION {
canonical_domain: ThermalMeasurements
interpretation_order:
identify_quantity
identify_value
identify_unit
identify_temperature_scale
distinguish_absolute_from_difference_temperature
identify_material_and_phase
identify_temperature_pressure_and_state_conditions
identify_heat_or_energy_context
identify_heat_transfer_mode
identify_geometry_and_system_boundary
identify_measurement_method
identify_uncertainty
normalize_units
validate_dimensions
infer_thermal_relationships
ambiguity_controls:
distinguish_temperature_from_heat
distinguish_heat_from_internal_energy
distinguish_heat_capacity_from_specific_heat_capacity
distinguish_thermal_conductivity_from_thermal_diffusivity
distinguish_heat_flux_from_heat_transfer_rate
distinguish_thermal_resistance_from_electrical_resistance
distinguish_absolute_temperature_from_temperature_difference
distinguish_sensible_heat_from_latent_heat
preserve_material_phase_pressure_and_reference_conditions
}
PROVENANCE {
ontology_scope:
mathematical_measurement_and_thermal_quantity_semantics
parent_path:
Ontologies
-> Mathematical Ontologies
-> Measurement & Units Ontologies
-> Thermal Measurements Ontology
authorship:
Mark Higgins
Sky (Recursive AI)
site:
https://kirethresearch.org
}
FLOW_HASH {
INPUTS:
canonical_domain
ontology_path
scope
temperature_model
heat_energy_distinction_model
sensible_heat_model
latent_heat_model
conduction_model
convection_model
radiation_model
thermal_expansion_model
thermal_diffusivity_model
heat_transfer_balance_model
entropy_model
units
relationships
constraints
measurement_model
reference_model
uncertainty_model
reasoning_rules
confidence_model
update_model
PURPOSE:
deterministic_semantic_integrity_identifier
RECOMPUTE_WHEN:
ontology_definition_changes
thermal_quantity_model_changes
heat_transfer_model_changes
material_property_model_changes
phase_change_model_changes
unit_or_scale_model_changes
measurement_model_changes
reference_model_changes
constraint_model_changes
reasoning_rule_changes
}
}
END FLOW