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 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. These are defined in NBS Monograph 125 as nickel-chromium alloy versus nickel-aluminum alloy thermocouples.
This SAE Aerospace Recommended Practice (ARP) defines the nomenclature of temperature measuring devices. General temperature measurement related terms are defined first, followed by nomenclature specific 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 stock, 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.
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.
SAE Aerospace Information Report AIR1871 provides valuable insight into lessons learned in the development, implementation, and operation of various health monitoring systems for propulsion engines and drive train systems. This document provides an overview of the lessons learned for ground-based systems, oil debris monitoring systems, lubrication systems, and Health and Usage Monitoring Systems (HUMS) for military and commercial programs. For each case study, this document presents a brief technical description, the design requirements, accomplishments, lessons learned, and future recommendations. The lessons learned presented in this document represent a fragment of the knowledge gained through experience when developing and implementing a propulsion health management system. Previous versions of this document contain additional lessons learned during the 1980’s and 1990’s that may be of additional value to the reader.
This SAE Aerospace Information Report (AIR) discusses physical and functional integration of main engine and auxiliary power unit (APU) monitoring with other on-board systems. It includes General Considerations, Parameter Selection and Requirements, Signal Sources, Signal Conditioning, Data Processing, Data Storage, and Data Retrieval. Engine monitoring hardware and software are discussed so that they may be properly considered in an integrated design. Civil and military aviation applications are included and delineated where requirements differ.
SAE Aerospace Information Report (AIR) 4061 provides best practice guidelines for the integration of Engine Health Management (EHM) system functions within aircraft systems to include both its main engine(s) and any Auxiliary Power Unit(s) (APU). This document provides an overview of some of the functions EHM typically integrates, offers some system variations encountered with different aircraft, and suggests general considerations involved with integration. It presents a sample EHM parameter coverage matrix to show the types of parameters with which a typical EHM system might interface, offers insight into signal and data processing and retrieval, and offers a view of typical EHM parameter requirements by function. Where practical, this document delineates between military and commercial practices.
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.
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.
This Aerospace Information Report (AIR) discusses physical and functional integration of main engine and auxiliary power unit (APU) monitoring with other on-board systems. It includes General Considerations, Parameter Selection and Requirements, Signal Sources, Signal Conditioning, Data Processing, Data Storage, and Data Retrieval. Engine monitoring hardware and software are discussed so that they may be properly considered in an integrated design. Civil and military aviation applications are included and delineated where requirements differ.
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.