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.
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.
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 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
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).