1、 AEROSPACESTANDARDSubmitted for recognition as an American National StandardMINIMUM PERFORMANCE STANDARDTEMPERATURE INSTRUMENTSSAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. Theuse of this report is entir
2、ely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is thesole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites
3、your writtencomments and suggestions.Copyright 1996 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.Land Sea Air and SpaceFor Advancing MobilityThe Engineering SocietyINTERNATIONAL400 Commonwealth Drive, Warrendale, PA 15096-0001Issued 1977-01Revised 1996-09REV.AS8005 AFOR
4、EWORDChanges in the revision are format/editorial only.1. SCOPE:This SAE Aerospace Standard (AS) applies to all temperature instruments used in aircraftapplications and environments. The word “instrument” as used in this Standard encompasses onlythe display device and does not include the temperatur
5、e sensors. Examples of the types ofinstruments covered are as follows:1.1 Temperature instruments using a Resistance Temperature Detector for temperature sensing.1.2 Temperature instruments using a thermocouple for temperature sensing.1.3 Temperature instruments using an averaging thermocouple harne
6、ss for temperature sensing.1.4 Temperature instruments receiving an input from a signal conditioning unit.1.5 Temperature instruments receiving an input from another temperature instrument.1.6 Temperature instruments receiving an input from other temperature sensing devices.1.7 Purpose:This document
7、 establishes the essential minimum performance requirements for electrical typetemperature instruments primarily for use on aircraft which may subject the instruments toenvironmental conditions specified herein.SAE AS8005 Revision A- 2 -2. APPLICABLE DOCUMENTS:The following publications form a part
8、of this document to the extent specified herein. The latestissue of SAE publications shall apply. The applicable issue of other publications shall be the issuein effect on the date of the purchase order. In the event of conflict between the text of thisdocument and references cited herein, the text
9、of this document takes precedence. Nothing in thisdocument, however, supersedes applicable laws and regulations unless a specific exemption hasbeen obtained.2.1 RTCA Publications:Available from RTCA Inc., 1140 Connecticut Avenue, NW, Suite 1020, Washington, DC 20036.RTCA Document No. DO-138, June 27
10、, 19682.2 FAA Publications:Available from Federal Aviation Administration, 800 Independence Avenue, SW, Washington, DC20591.Federal Aviation Regulations, Vol. III, Part 25Airworthiness Standards: Transport Category Airplanes3. GENERAL STANDARDS:3.1 Classification by Instrument Accuracies:Class I Cla
11、ss Ia: 0.1% of indicated rangeClass Ib: 0.2% of indicated rangeClass Ic: 0.5% of indicated rangeClass II Class IIa: 1% of indicated rangeClass III Class IIIa: 2% of indicated rangeClass IIIb: 3% of indicated rangeClass IIIc: 5% of indicated range3.2 Method of Indication:3.2.1 If applicable, relative
12、 motion of the index with respect to the scale (either the index or the scalemay be the moving element) shall be clockwise, up, or to the right for increasing temperature.3.2.2 Sufficient numerals and graduations shall be provided to positively and quickly identifytemperature indications. The inscri
13、ption “C”, “F”, or “K”, as appropriate, shall also appear onthe instrument face.SAE AS8005 Revision A- 3 -3.2.3 Indications beyond the normal range of the instrument shall not be displayed in a mannerinterpretable as an on-scale reading or as an off-scale reading in the wrong direction.3.3 Power Mal
14、function:Means (e.g. warning flags, off-scale indication) shall be incorporated in the instrument to indicatethe loss of essential power for proper operation of the indicator. This does not apply to the lossof signal used to drive the instrument where no other power is used.3.4 Markings:Where termin
15、al posts are used for thermocouple connections, they shall be of different sizes andshall be distinctly identified to indicate plus for the larger terminal, and minus for the smallerterminal. The thermocouple material, and when applicable, the required external resistance ofthe lead and thermocouple
16、, or the thermocouple circuit shall be plainly marked.3.5 Signal (Sensor) Characteristics:Instruments shall be calibrated to indicate temperature in accordance with the signalcharacteristic specified by the manufacturer of the instrument in his installation instructions.3.6 Adjustments:When provided
17、, external adjustment provisions shall have sufficient friction so that they will notchange in the environment encountered in service.3.7 Accessibility of Controls:Controls which are not normally adjusted in flight shall not be readily accessible to flightpersonnel when the equipment is installed in
18、 accordance with the manufacturers instructions.3.8 Effects of Tests:Unless otherwise stated, the application of the specified tests shall produce no subsequentlydiscernible condition which would be detrimental to the continued performance of the equipment.3.9 Interchangeability:Instruments and comp
19、onents which are identified in accordance with the requirements applicableto this standard and are identified with a manufacturers part and/or model number shall bedirectly and completely interchangeable with all items identified with that part and/or modelnumber.SAE AS8005 Revision A- 4 -3.10 Fire
20、Resistance:Except for small parts (such as knobs, fasteners, seals, grommets, and small electrical parts)that would not contribute significantly to the propagation of a fire, all materials used must beself-extinguishing when tested in accordance with the requirements of Federal AviationRegulation 25
21、.1359 (d) and Appendix F thereto, with the exception that materials tested may beconfigured in accordance with paragraph (b) of Appendix F or may be configured as used.3.11 Instrument Cover Glass Reflectance:The total reflectance of the instrument cover glass including the integral lighting wedge, i
22、fapplicable, shall not exceed 10% of the incident light. This reflectance applies over the visiblelight spectrum from 450 milli-microns to 600 milli-microns, and over an incident solid angle of60 perpendicular to the viewing plane.4. MINIMUM PERFORMANCE STANDARDS UNDER STANDARD CONDITIONS:4.1 Standa
23、rd Atmospheric Conditions:Unless otherwise specified herein, all tests required shall be made at atmospheric conditionsspecified in paragraph 3.4 of DO-138.4.2 Attitude:Unless otherwise specified herein, all tests shall be conducted with the instrument in its normaloperating attitude.4.3 Vibration t
24、o Minimize Friction:Unless otherwise specified herein, all tests for performance may be conducted in accordance withinstructions found in paragraph 3.5 of DO-138.4.4 Power Input Voltage:4.4.1 Direct Current: Unless otherwise specified, when the equipment is designed for operation froma current power
25、 source, all measurements shall be conducted with the power input voltageadjusted to 13.75 volts 2% for 10 - 14 volt equipment or 27.5 volts 2% for 24 - 28 voltequipment. The power input voltage shall be measured at the power input terminals.4.4.2 Alternating Current: Unless otherwise specified, whe
26、n the equipment is designed for operationfrom an alternating current power source all tests shall be conducted with the power inputvoltage adjusted to design voltage 2 percent. In the case of equipment designed for operationfrom a power source of essentially constant frequency (e.g. 400 Hz), the inp
27、ut frequency shallbe adjusted to design frequency 1 percent. In the case of equipment designed for operationfrom a power source of variable frequency (e.g. 350 - 1,000 Hz), tests shall be conducted withthe input frequency adjusted to within 5% of the high frequency limit, the low frequency limit,and
28、 the mid frequency (test at three frequencies).SAE AS8005 Revision A- 5 -4.5 Scale Error:4.5.1 With the appropriate signal applied, the scale error shall be determined at not less than 5 testpoints, each taken in a different 1/5 of the scale range, and shall not exceed the scale errortolerances of t
29、he specific class of instrument involved as shown in 3.1.4.5.2 In the event that a non-uniform tolerance is required, compliance with 4.5.1 is demonstrated ifthe error at any calibration point does not exceed the value appropriate for that point.4.6 Position Error:4.6.1 If the instrument is potentia
30、lly subject to position (balance) error, the instrument shall beelectrically energized and a reading shall be taken while in each of the following positions:1. Normal operating attitude.2. Instrument rotated clockwise around its X (longitudinal) axis, 180 degrees from its normalposition.3. Instrumen
31、t rotated clockwise around its X (longitudinal) axis, 90 degrees from its normalposition.4. Instrument rotated counter-clockwise around its X (longitudinal) axis, 90 degrees from itsnormal position.4.6.2 The maximum change in reading from the normal shall not exceed the tolerance of thespecific clas
32、s of instrument involved.4.7 Lead Resistance Effect:For instruments using a resistance temperature detector, where the ground lead is connected atthe detector, there shall not be a change in indication at any point on the scale due to changingthe balanced lead resistance, more than that allowable fo
33、r the class of instrument involved,provided the instrument is installed in accordance with the manufacturers installation instructions.4.8 Friction Error:The friction test may be conducted in conjunction with the scale error test. The signal shall beslowly increased up to the test point. The instrum
34、ent reading shall be noted before and after theinstrument is lightly tapped or vibrated. The change in reading must not exceed the toleranceallowed for the particular class of instrument involved. The above procedure shall be repeated fordecreasing signal values.SAE AS8005 Revision A- 6 -4.9 Magneti
35、c Effect:The magnetic effect of the instrument shall be determined in terms of the deflection of a freemagnet, approximately 1-1/2 inches (3.81 cm) long, in a magnetic field with a horizontal intensityof 0.18 0.01 gauss when the instrument is held in various positions on an east-west line with thene
36、arest part 12 inches (30.48 cm) from the center of the magnet. With the instrument operating,the maximum deflection of the free magnet shall not exceed 5 degrees from an indicating orreference position.5. MINIMUM PERFORMANCE STANDARDS UNDER ENVIRONMENTAL CONDITIONS:Unless otherwise specified, the me
37、asurement procedures applicable to a determination of theperformance of temperature instruments under environmental conditions are set forth in RTCADocument Number DO-138 entitled “Environmental Conditions and Test Proc. for AirborneElectronic/Electrical Equipment and Instruments”, dated 27 June 196
38、8. Performance tests whichcannot be made after subjection to test environments may be conducted after exposure to severalenvironmental conditions. The order of tests shall be in accordance with paragraph 3.2, page 5,DO-138.5.1 Temperature Altitude:5.1.1 Low Temperature: When subjected to the tests o
39、f DO-138, paragraph 4.1, the instrument shalloperate electrically and mechanically and the requirements of 4.5 of this standard must be metexcept that a tolerance of two times that of the class involved shall apply. After subjection tothis test, the requirements of 4.5 and 4.8 of this standard shall
40、 be met under standardconditions.5.1.2 High Temperature: When subjected to the tests of DO-138, paragraph 4.2.1, the instrumentshall operate electrically and mechanically and there shall be no evidence of materials such asgrease, potting, or sealing compounds exuding or dripping from the instrument.
41、 Whensubjected to the tests of DO-138, paragraph 4.2.2, the instrument shall operate electrically andmechanically and the requirements of 4.5 of this standard shall be met except that a toleranceof two times that of the class involved shall apply. After subjection to this test, the requirementsof 4.
42、5 and 4.8 of this standard shall be met under standard conditions.5.1.3 Altitude: When subjected to the tests of DO-138, paragraph 4.3.1, the instrument shall operateelectrically and mechanically and the requirements of 4.5 of this standard shall be met. Afterthe tests of paragraph 4.3.2, DO-138, th
43、e requirements of 4.5 and 4.8 of this standard shall bemet at standard conditions, and after the tests of 4.3.3, DO-138, the requirements of 4.5 and4.8 of this standard shall be met at standard conditions.5.2 Power Input:5.2.1 Electrical Input Variation Test:SAE AS8005 Revision A- 7 -5.2.1.1 When th
44、e instrument is subjected to the test in DO-138, paragraph 9.1B, it shall operateelectrically and mechanically and meet the requirements of 4.5 of this standard except thatthe indications at the increased voltage shall not differ from the indications at nominal testvoltage by more than that allowed
45、by the class of instrument being tested.5.2.1.2 When the instrument is subjected to the tests in paragraph 9.1D, it shall operate electricallyand mechanically and meet the requirements of 4.5 of this standard except that theindications at the reduced voltage shall not differ from the indications at
46、nominal test voltageby more than that allowed by the class of instrument being tested.5.2.2 Low Voltage Test:5.2.2.1 When the instrument is subjected to the tests of DO-138, paragraph 9.2.1, it shall operateelectrically and then meet the requirements of 4.5 of this standard except that the indicatio
47、nsat decreased voltage shall not differ from the indications at nominal test voltage by more thanthat allowed by the class of instrument being tested.5.2.2.2 When the instrument is subjected to the tests in DO-138, paragraph 9.2.2A, it shall operateelectrically and mechanically and meet the requirem
48、ents of 4.5 of this standard.5.2.2.3 When the instrument is subjected to the tests in DO-138, paragraph 9.2.2B, there shall be noevidence of the presence of fire or smoke. Following the tests, the instrument shall meet therequirements of 4.5 of this standard at standard conditions.5.3 Conducted Volt
49、age Transients:5.3.1 Intermittent Transients: Following the tests of DO-138, paragraph 10.1.1, the instrument shallmeet the requirements of 4.5 of this standard at standard conditions.5.3.2 Repetitive Transients: When the instrument is subjected to the tests of DO-138, paragraph10.1.2, it shall meet the requirements of 4.5 of this standard.5.3.3 Interconnecting Wiring Induced Transients: When the instrument is subjected to the tests ofDO-138, paragraph 10.1.3, it shall meet the requirements of 4.5 of this standard.5.3.4 Equipment Operated from AC Power: When the ins
