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The NET EMF of a thermoelectric circuit can be thought of as originating entirely in the regions of temperature gradient. Any extraneous materials, such as switch or connector terminals, in a temperature gradient may cause an error in the temperature measurement. In addition to circuitry errors, jet engine thermocouple indications require correction for the effects of conduction, radiation, response rate, and gas velocity. The magnitudes of the corrections depend on the thermocouple design and the environmental conditions. Performance curves for several typical jet engine thermocouples are presented, with the methods of making the various corrections.

This SAE Aerospace Information Report (AIR) reviews the precautions that must be taken and the corrections which must be evaluated and applied if the experimental error in measuring the temperature of a hot gas stream with a thermocouple is to be kept to a practicable minimum. Discussions will focus on Type K thermocouples, as defined in National Institute of Standards and Technology (NIST) Monograph 175 as Type K, nickel-chromium (Kp) alloy versus nickel-aluminium (Kn) alloy (or nickel-silicon alloy) thermocouples. However, the majority of the content is relevant to any thermocouple type used in gas turbine applications.

This SAE Aerospace Recommended Practice (ARP) defines the nomenclature of temperature measuring devices. General temperature measurement related terms are defined first, followed by nomenclature specifice to temperature measuring devices, particularly thermocouples.

The thermocouple design recommended herein is presented as one for which the correction to the observed emf, because of thermal conduction along the stem and wires, is within the limits presented in the accompanying figure. On referring to the figure, it is seen that no restriction is placed upon the diameter of the thermocouple or stem, and the longitudinal dimensions are expressed in terms of wire and stem diameters. The type of stem, such as packed ceramic stick, refractory insulating tubing, etc., also is left open to choice. Thus the sizes of wires and supporting stems may be varied over wide ranges to match particular requirements where conduction errors are to be limited or controlled.

To establish a specification for software input and output interfaces for condition monitoring and performance programs used to monitor equipment from multiple manufacturers. The purpose of standardizing these interfaces is to improve operational flexibility and efficiency of monitoring systems as an aid to cost effectiveness (e.g., easier implementation).

The ice bath recommended herein is similar to that described in SAE AIR 46. Some material not presented in AIR 46, including preferred dimensions, has been added.

The SAE E-32 Committee is requested to develop standards for Commercial Aircraft Engine Monitoring to support the Continued Airworthiness of aircraft in general, with particular emphasis on the ETOPS (Extended Operations) to support the regulations. 14CFR A33.3 (c) ETOPS Requirements. For an applicant seeking eligibility for an engine to be installed on an airplane approved for ETOPS, the Instructions for Continued Airworthiness must include procedures for engine condition monitoring. The engine condition monitoring procedures must be able to determine prior to flight, whether an engine is capable of providing, within approved engine operating limits, maximum continuous power or thrust, bleed air, and power extraction required for a relevant engine inoperative diversion. For an engine to be installed on a two-engine airplane approved for ETOPS, the engine condition monitoring procedures must be validated before ETOPS eligibility is granted.

This document applies to prognostics of gas turbine engines and its related auxiliary and subsystems. Its purpose is to define the meaning of prognostics with regard to gas turbine engines and related subsystems, explain its potential and limitations, and to provide guidelines for potential approaches for use in existing condition monitoring environments. It also includes some examples.

This document applies to prognostics of aerospace propulsion systems. Its purpose is to define the meaning of prognostics in this context, explain their potential and limitations, and to provide guidelines for potential approaches for use in existing condition monitoring environments. This document also includes some examples. The current revision does not provide specific guidance on validation and verification, nor does it address implementation aspects such as computational capability or certification.

Scope is unavailable.

This Aerospace Information Report (AIR) presents considerations specific to machine learning (ML) applied to propulsion system health management (aka EHM), illustrated via examples. These examples are used to highlight concerns and approaches that are unique to EHM, including the typical design space for propulsion systems, terminology, data collection and processing methods, requirements, and characteristics of machine learning models that have been developed and are being implemented.

The effectiveness of Engine Life Usage Monitoring and Parts Management systems is largely determined by the aircraft-specific requirements. This document addresses the following areas: a Safety b Life-limiting criteria c Life usage algorithm development d Data acquisition and management e Parts life tracking f Design feedback g Cost effectiveness It primarily examines the requirements and techniques currently in use, and considers the potential impact of new technology to the following areas: a Parts classification and control requirements b Failure causes of life-limited parts c Engine life prediction and usage measurement techniques d Method validation e Parts life usage data management f Lessons learned g Life usage tracking benefits

This SAE Aerospace Information Report (AIR) provides information and guidance for the selection and use of technologies and methods for lubrication system monitoring of gas turbine aircraft engines. This AIR describes technologies and methods covering oil system performance monitoring, oil debris monitoring, and oil condition monitoring. Both on-aircraft and off-aircraft applications are presented. A higher-level view of lubrication system monitoring as part of an overall engine monitoring system (EMS), is discussed in ARP1587. The scope of this document is limited to those lubrication system monitoring, inspection and analysis methods and devices that can be considered appropriate for health monitoring and routine maintenance. This AIR is intended to be used as a technical guide. It is not intended to be used as a legal document or standard.

This SAE Aerospace Information Report (AIR) provides information and guidance for the selection and use of technologies and methods for lubrication system monitoring of gas turbine aircraft engines. This AIR describes technologies and methods covering oil system performance monitoring, oil debris monitoring, and oil condition monitoring. Both on-aircraft and off-aircraft applications are presented. A higher-level view of lubrication system monitoring as part of an overall engine monitoring system (EMS), is discussed in ARP1587. The scope of this document is limited to those lubrication system monitoring, inspection and analysis methods and devices that can be considered appropriate for health monitoring and routine maintenance. This AIR is intended to be used as a technical guide. It is not intended to be used as a legal document or standard.

The purpose of this SAE Aerospace Information Report (AIR) is to provide information and guidance for the selection and use of lubrication system monitoring methods. This AIR is intended to be used as a technical guide. It is not intended to be used as a legal document or standard. The scope of this document is limited to those inspection and analysis methods and devices that can be considered appropriate for routine maintenance.

The purpose of this Aerospace Information Report (AIR) is to provide information and guidance for the selection and use of oil system monitoring devices and methods. This AIR is intended to be used as a technical guide. It is not intended to be used as a legal document or standard. The scope of this document is limited to those inspection and analysis methods and devices which can be considered appropriate for routine maintenance. In agreement with industry usage, wear particle size ranges are given in μm (1 μm = 10-3 millimeter = 10-6 meter). Other dimensions are given in millimeters, with inches in parenthesis.

The effectiveness of Engine Life Usage Monitoring and Parts Management systems is largely determined by the aircraft-specific requirements. This AIR addresses the following areas: a Safety. b Life-limiting criteria. c Life usage algorithm development. d Data acquisition and management. e Parts life tracking. f Design feedback. g Cost effectiveness. This AIR primarily examines the requirements and techniques currently in use, including: a Parts classification and control requirements. b Failure causes of life-limited parts. c Engine life prediction and usage measurement techniques. d Method validation. e Parts life usage data management. f Lessons learned. g Life usage tracking benefits.

The purpose of this SAE Aerospace Information Report (AIR) is to provide information and guidance for the selection and use of oil system monitoring devices and methods. This AIR is intended to be used as a technical guide. It is not intended to be used as a legal document or standard. The scope of this document is limited to those inspection and analysis methods and devices that can be considered appropriate for routine maintenance. In agreement with industry usage, wear particle size ranges are given in micrometers (1 μm = 10-3 mm = 10-6 m).

This SAE Aerospace Recommended Practice (ARP) provides guidance for the design of flanges on temperature sensors intended for use in gas turbine engines. Three figures detail the configuration of standard size flange mounts with bolt holes, slotted flanges, and miniaturized flanges for small probes.