1、AEROSPACESTANDARDAS412 REV.BIssued 1948-11Reaffirmed 2008-02Revised 2001-07Superseding AS412ACarbon Monoxide Detector InstrumentsFOREWORDChanges in this Revision are format/editorial only.1. SCOPE:This Aeronautical Standard covers the basic type of carbon monoxide detector instrument used to determi
2、ne toxic concentrations of carbon monoxide by the measurement of heat changes through catalytic oxidation.1.1 Purpose:To specify minimum requirements for carbon monoxide detector instruments for use in aircraft, the operation of which may subject the instrument to the environmental conditions specif
3、ied in Paragraph 3.3. This standard is not intended to cover fire detectors.2. REFERENCES:There are no referenced publications specified herein.3. GENERAL REQUIREMENTS:3.1 Material and Workmanship:3.1.1 Materials: Materials shall be of a quality which experience and/or tests have demonstrated to be
4、suitable and dependable for use in aircraft instruments.3.1.2 Workmanship: Workmanship shall be consistent with high grade aircraft instrument manufacturing practice.SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering s
5、ciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaff
6、irmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2008 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, record
7、ing, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE AS412 Revision B- 2 -3.2 Identification:The foll
8、owing information shall be legibly and permanently marked on the instrument or attached thereto:(a) Name of instrument (Carbon Monoxide Detector)(b) SAE Aeronautical Standard AS412B(c) Manufacturers part number(d) Manufacturers serial number of date of manufacture(e) Manufacturers name and/or tradem
9、ark(f) Rating3.3 Environmental Conditions:The following conditions have been established as design requirements only. Tests shall be conducted as specified in Sections 5, 6, and 7.3.3.1 Temperature: When installed in accordance with the instrument manufacturers instructions, the instrument shall fun
10、ction over the range of ambient temperature indicated in Column A below, and shall not be adversely affected by exposure to the temperatures shown in Column B below.3.3.2 Humidity: The instrument shall function and shall not be adversely affected when exposed to any relative humidity in the range fr
11、om 0 to 95 percent at a temperature of approximately 32 C.3.3.3 Altitude: The instrument shall function and not be adversely affected when subjected to a pressure and temperature range equivalent to -1000 feet to 40,000 feet standard altitude except that the instrument temperature shall not be lower
12、 than -30 C.TABLE 1Instrument Location A BHeated Areas (Temp. controlled) -30 to 50 C -65 to 70 CUnheated Areas (Temp. uncontrolled) -55 to 70 C -65 to 70 CSAE AS412 Revision B- 3 -3.3.4 Vibration: When installed in accordance with the instrument manufacturers instructions, the instruments shall fun
13、ction and shall not be adversely affected when subjected to vibrations of the following characteristics:4. DETAIL REQUIREMENTS:4.1 Design:The instrument shall consist of a means for testing air for contamination with carbon monoxide. It shall include an alarm circuit or control circuit which will in
14、dicate the presence of contamination when it reaches a concentration between .005 and .007 percent of carbon monoxide by volume.4.1.1 Sampling Method: A means shall be incorporated in the design to direct the air sample to the sensitive element of the instrument in a positive manner.4.2 Indicating M
15、ethod:The instrument shall be capable of actuating both visual and aural alarm indicators.4.3 Reliability:False signals (including failure) in the instrument shall not result from variations in flight attitude, from normal amounts of gasoline vapors and dust likely to accumulate in the instrument in
16、 normal flight operations, from accelerations encountered in flight or landing, or from variations in voltage (+25 percent, -100 percent of the rated).4.4 Power Variations:All units shall properly function with +10 percent -20 percent variation in DC voltage and/or 10 percent variation in AC voltage
17、 and 5 percent variation in frequency.TABLE 2Type of Instrument Mounting Cycles/MinMaximum DoubleAmplitudeMaximumAccelerationAirframe Structure Mounted 300 - 30,000 .036 inch 10 gShock Mounted Panel or ShockMounted Rack 300 - 3,000 .020 inch 1.5 gSAE AS412 Revision B- 4 -5. TEST CONDITIONS:5.1 Atmos
18、pheric Conditions:Unless otherwise specified, all tests required by this Aeronautical Standard shall be conducted at an atmospheric pressure of approximately 29.92 inches of mercury and at an ambient temperature of approximately 22 C. When tests are conducted with the atmospheric pressure or the tem
19、perature substantially different from these values, allowance shall be made for the variation from the specified conditions.5.2 Vibration:(To minimize friction.) Unless otherwise specified, all tests for performance may be conducted with the instrument subjected to a vibration of 0.002 to 0.005 inch
20、 double amplitude at a frequency of 1500 to 2000 cycles per minute. The term double amplitude as used herein indicates the total displacement from positive maximum to negative maximum.5.3 Vibration Equipment:Vibration equipment shall be used which will provide frequencies and amplitudes consistent w
21、ith the requirements of Paragraph 3.3.4 with the following characteristics:5.3.1 Linear Motion Vibration: Vibration equipment for airframe structure mounted instruments shall be such as to allow vibration to be applied along each of three mutually perpendicular axes of the test specimen.5.3.2 Circul
22、ar Motion Vibration: Vibration equipment for shock mounted panel instruments shall be such that a point on the instrument case will describe, in a plane 45 to the horizontal plane, a circle the diameter of which is equal to the double amplitude specified.5.4 Power Conditions:Unless otherwise specifi
23、ed, all tests shall be conducted at a power rating recommended by the manufacturer.5.5 Position:Unless otherwise specified, all tests shall be conducted with the instrument mounted in its normal operating position.5.6 Air Sample:Unless otherwise specified, the air sample shall be air containing 0.00
24、75 percent 0.0005 percent of carbon monoxide by volume.SAE AS412 Revision B- 5 -6. INDIVIDUAL PERFORMANCE REQUIREMENTS:All instruments or components of such shall be subjected to whatever tests the manufacturer deems necessary to demonstrate specific compliance with this Aeronautical Standard, inclu
25、ding the following requirements where applicable:6.1 Response Time:The instrument shall be tested so that, when an air sample per Paragraph 5.6 is introduced, the alarm circuit or control circuit shall be energized within a maximum of 5 minutes.7. QUALIFICATION TESTS:As many instruments as deemed ne
26、cessary to demonstrate that all instruments will comply with the requirements of this section shall be tested in accordance with the manufacturers recommendations.7.1 Stability:The instrument shall be operated continuously for twenty-four hours at room temperature. At the end of the first and twenty
27、-fourth hour of operation a sample of air, per Paragraph 5.6 shall be introduced into the instrument and the time required for operation of the alarm circuit or control circuit at the end of the twenty-fourth hour shall not exceed that observed at the end of the first hour of this run by more than 3
28、0 seconds and in no case shall it exceed the time specified in Paragraph 6.1.7.2 Suction Variation:The instrument shall be operated continuously by varying the suction from 25 percent below to 25 percent above the normal rated suction. At each of these values a sample of air, per Paragraph 5.6, shal
29、l be introduced and the time required for operation of the alarm circuit or control circuit shall not differ from that observed under the normal response time test at normal rated suction, by more than 30 seconds, and in no case shall it exceed the time specified in Paragraph 6.1.7.3 Voltage Variati
30、ons:The instrument shall be operated at any voltage within the range of Paragraph 4.4. The instrument shall then be tested with an air sample, per Paragraph 5.6, and the response time shall not vary from that at the rated by more than 30 seconds, and in no case shall it exceed the time specified in
31、Paragraph 6.1.7.4 High Temperature:The instrument shall be exposed to a temperature of 60 C, and at this temperature, the time of response shall not exceed that specified for room temperature by more than 60 seconds, and in no case shall it exceed the time specified in Paragraph 6.1.SAE AS412 Revisi
32、on B- 6 -7.5 Low Temperature:The instrument shall be exposed to a temperature of -65 C for a period of 48 hours, after which it shall be raised to a temperature of -55 C. After operating for thirty minutes at a temperature of -55 C, the rate of response shall not exceed the time specified at room te
33、mperature by more than60 seconds, and in no case shall it exceed the time specified in Paragraph 6.1.7.6 Humidity:The instrument shall be subjected to the conditions specified in Paragraph 3.3.2 for a period of 10 hours, after which it shall meet the requirements of Paragraph 6.1.7.7 Altitude Effect
34、:Tests shall be conducted at an altitude pressure equivalent to 25,000 feet and under these conditions the time of response shall not be increased by more than 60 seconds over sea level conditions and in no case shall it exceed the time specified in Paragraph 6.1. The instrument shall then be placed
35、 in a pressure altitude equivalent to 40,000 feet and at that pressure tested with air. No false alarm shall result.7.8 Vibration:The instrument while operating normally shall be subjected to vibrations of all frequencies within the appropriate range specified in Paragraph 3.3.4 in order to determin
36、e if there exists any natural frequencies of any parts that lie within the specified range. The amplitude used may be any convenient value that does not exceed the maximum double amplitude specified in Paragraph 3.3.4 and such as not to exceed the maximum acceleration specified in Paragraph 3.3.4.Th
37、e instrument shall then be subjected to vibration at the appropriate maximum double amplitude or maximum acceleration specified in Paragraph 3.3.4 at each of the above determined natural frequencies for a period of three hours. If no natural frequencies occurred in the appropriate frequency range, t
38、he frequencies and double amplitude for this endurance test should be determined from the following table:TABLE 3Cycles per Minute Double AmplitudeAirframe Structure Mounted 3000 .036Shock Mounted Panel or Shock MountedRack 3000 .010SAE AS412 Revision B- 7 -7.8 (Continued):No damage shall be evident
39、 and the instrument shall meet the requirements of Section 6. During this time no false alarm shall be given. The time required for a response to a sample while under vibration, per Paragraph 5.6, shall not vary from that observed under normal conditions before the vibration test by more than 60 sec
40、onds, and in no case more than the time specified in Paragraph 6.1.7.9 Contamination Tests:Air contaminated with 100 octane gasoline in concentration of 1000 parts per million by volume shall be passed through the instrument continuously for a period of 2 hours, after which an air sample per Paragra
41、ph 5.6 shall be passed through the instrument. The time shall not exceed that specified in Paragraph 6.1, and during the passage of the gasoline contaminated air through the instrument, no false alarms shall result. In the event that it is impractical to maintain a vapor concentration of 1000 parts per million, the length of test shall be varied in inverse proportion to the concentration for variations within 25 percent of the specified concentration.PREPARED BY SAE COMMITTEE A-4, AIRCRAFT INSTRUMENTS
