1、a AEROSPACE SPACE STAN DARD Society 400 COMMONWEALTH of Automotive DRIVE. WARRENDALE. Engineers, PA. i5096 Inc. 1.0 PURPOSE AS 8028 Issued pril, 1980 Revised This Standard establishes minimum requirements for powerplant fire detection instruments primarily for use in reciprocating and turbine engine
2、 powered aircraft. 2.0 SCOPE 2.1 This Standard covers the following basic types of fire detection instruments, or combinations thereof, intended for use in protecting aircraft powerplant installation, auxiliary powerplants, combustion heaters and other installations where fuel, oil or similar fires
3、may occur. 2.2 Types Type 1: Thermal - Fixed Temperature, an instrument which will actuat an alarm signal when exposed to any temperature above a definite pre-established level. Type II: Thermal - Rate of Rise, an instrument which will actuate an alarm signal when exposed to any rate of temperature
4、change above a definite pre-established level. Type III: Flame - Contact, an instrument which will actuate an alarm signal when exposed to physical contact with flame. 2.3 Range The range and/or setting of the instrument shall be as marked on the instrument. 2.4 equipment category is to be as specif
5、ied by the manufacturer, A-ternate approved test procedures that provide equivalent results may be used. many instruments as deemed necessary to demonstrate that the instruments comply with the requirements of this section shall be tested in accordance with the manufacturers recommendations. After t
6、he tests have been initiated, further adjustments to the instrument shall not be permitted. A false alarm signal occurring during any of the tests shall disqualify the instrument from further testing. 5.1 Response Time and Calibration: Each instrument shall be subjected to the response time and cali
7、bration tests listed below applicable to the particular type or combination thereof. Instruments shall be tested by the application of the test flame to a single unit type sensor or to a 6 in. (15.24 cm) length of continuous type sensor. For instruments in which the sensitivity is affected by the nu
8、mber of sensing elements, by the length of the sensing element (for continuous types) or by other factors which may be varied from one installation to another, all response ,time tests shall be conducted with the least sensitive configuration to be used. The unit sensor or segment of continuous sens
9、or expos.ed to the test flame shall be that most critical for response time. As SAE ASWOZ ao a a357340 aa:wwy Y m -7- . AS 8028 . =. 5.1.1 Response Time Test - Types, 1, TI and III: The sensor of the instrumpt shal and the require- ments of paragraph 5.1 of this standard must be met. Vibration test
10、requirements by aircraft type and equipment location as noted in section 3.7.4 shall be specified by the manufacturer. 5.7 Shock Test: After subjection to the tests of DO-160, paragraph 7.0, the instrument must operate electrically and mechanically, and the requirements of paragraph 5.1 of this stan
11、dard must be met. 5.8 Humidity: Immediately following subjection to the tests of DO-160, paragsaph 6.3.2, severe humidity environment, except at a temperature of 65 C (149 F), the requirements of paragraph 5.1 of this standard must be met. a) Five times for component location in uncontrolled tempera
12、ture b) Once for component location in controlled temperature areas. areas. Immediately after this cycling, there shall be no evidence of damage or corrosion which affects performance. 5.9 Power Input: 5.9.1 Normal electrical input variation test. When subjected to the tests of DO-160, paragraphs 16
13、.3.1.1 or 16.3.2.1, the instrument must operate electrically and mechanically and meet the require- ments of paragraph 5.1 of this standard. 5.9.2 Abnormal electrical input variation test. When subjected to the tests of DO-160, paragraph 16.3.3.1 or 16.3.4.1, the instruments must operate electricall
14、y and mechanically; and degradation of performance is permissible. After returning to normal electrical input, the instrument must meet the requirements of paragraph 5.1 of this standard. 5.10 Voltage spike conducted test: The instrument: shall be subjected to the tests of DO-160, paragraph 17.0. Af
15、ter completion of the test, the instrument shall meet the requirements of paragraph 5.1 of this standard 5.11 Audio frequency conducted susceptibility test: The instrument shall be subjected to the tests of DO-160, paragraph 18.0. During the test, the instrument must operate electrically and mechani
16、cally and shall meet the requirements of paragraph 5.1 of this standard. - Induced Signal Susceptibility Test: The instrument shall be subjected to the tests of DO-160, paragraph 19.0. During the tests, the instrumen must operate electrically and mechanically, and must meet: the require- ments of pa
17、ragraph 5.1 of this standard. 5.12 I SAE AS*8028 80 = 8357340 00342LL 2 W -9- AS 8028 * 5.21 Salt spray: Instruments which are to be marked Salt Spray Category S must be tested in accordance with DO-160, paragraph -14. O test, the instrument must meet the requirements of paragraphs 5.1 of this stand
18、ard. Following this J a l 5.13 Radio frequency susceptibility test, radiated and conducted: The instrument shall be subjected to the tests of DO-160, paragraph 20.0. During the tests, the instrument must operate electrically and mechan- ically, and must meet the requirements of paragraph 5.1 of this
19、 standard 5.14 Emission of radio frequency energy test: The instrument shall be subjected to the tests of DO-160, paragraph 21.0. During the test, the instrument shall operate electrically and mechanically. After completion of the tests, the instrument shall meet requirements of paragraph 5.1 of thi
20、s standard. 5.15 Explosion: Instruments which are to be marked Explosion Category E must be tested in accordance with DO-160, paragraph 9.0. 5.16 Waterproofness: Instruments which are to be marked Waterproofness Category W must be tested in accordance with DO-160, paragraph 10.0. Following this test
21、, the instrument must meet the requirements of paragraph 5.1 of this standard. 5.17 Hydraulic fluid: Instruments which ere to be marked Hydraulic Fluid Category H must be tested, together with mating connectors, in accord- ance with DO-160, paragraph 11.0. Following exposure of the instrument and ma
22、ting connectors to the test environment, the instrument must meet the requirements of paragraph 5.1 of this standard. 5.18 Fuel and Oil Immersion: The instrument components, together with mating connectors, which are to be installed in engine compartments or other locations in the aircraft where it
23、may be contaminated by fuel or oil shall be subjected to the following tests: 5.18.1 Fuel Immersion: The component shall be thoroughly immersed in engine fuel at approximately room temperature and then allowed to drain for one (i) minute before being tested per Section 5.1. No cleaning other than th
24、e drainage as specified shall be accomplished prior to conducting subsequent tests. Components for reciprocating engines will be immersed in normally leaded 100 octane fuel. Components for turbine engines will be immersed in turbine engine fuel. 5.18.2 Oil Immersion: The test procedure outlined in S
25、ection 5.18.1 shall be conducted with used SAE oil if components are for reciprocating engines, and with used MIL-0-7808 oil or other applicable oil if components are for turbine engines. 5.19 Sand and dust: Instruments which are to be marked Sand and Dust Category D must be tested in accordance wit
26、h DO-160, paragraph 12.0. Following this test, the instrument must meet the requirements of paragraph 5.1 of this standard. 5.20 Fungus resistance: Instruments which are to be marked Fungus Resistance Category F must be tested in accordance with DO-160, paragraph 13.0. Foilowing this test, the instr
27、ument must meet the requirement of paragraphs 5.1 of this standard. SAE AS*8028 80 I 8357340 0034232 I AS 8028 - 10 - 5.22 Clearance Time : The instrument components which are to be .installed in aofire zoBe shall be subjected to a flame of a temperature of 1100 C (2012 F) minimum f,or two periods o
28、f one minute each, The flame shall be as specified in Figure 2. The components shall be cooled to approximately room temperature or to the ambient temperature permitted in Paragraph 5.1 after each exposure to the flame. The component shall then be exposed to the flame a third time. An alarm signal s
29、hall occur not to exceed five (5) seconds after each expousure to the flame, During cooling of the component after the first two exposures to flame, the alarm shall clear in not more than 45 seconds after the flame has been removed after each exposure, air velocity over the sensor shall be zero duri
30、ng the cooling portion of this test, except a specific higher velocity may be established providing the sensor is specified for use in areas where the air velocity under normal operating conditions will not decrease below this value. Artifickal means of cooling the component shall not be used until
31、after the alarm has cleared. A manual resetting means may be used to clear the alarm provided it is demonstrated that the resetting means will clear the alarm only if the flame has been removed. After the third exposure of the component to flame, the instrument need not be capable of further operati
32、on. During this test, the sensor shall be subjected to vibration with frequency and amplitude as specified in paragraph 5.6. The established 6.0 Minimum Acceptance Test Requirements Under Standard Conditions: Tests shall be performed on each Fire Detection Instrument produced to show compliance with
33、 the following paragraphs of this standard. 3.6 Identification 3.11 Indication means 4.7.1 Sensitivity and Calibration 4.7.2 Dielectric PREPARED BY COMMITTEE A-4, AIRCRAFT INSTRUMENTS SAE AS*B02B BO W 8357340 0034213 b I - 11 - I AS8028 O 1 O0 175 200 3 O0 400 450 deg F/min 55.6 972 111.1 166.7 222.
34、2 250 deg C/min Rate of temperature rise FIGURE 1 (a) Local temperature rise condition (Ref. Section 5.2.1) O 50 100 deg F/min O 27 . 55.6 deg C/min Rate of temperature rise FIGURE 1 (b) (Ref. Section 5.2.2) General temperature rise condi tion _I_- - SAE ASr8028 BO m 8357340 00342/4 B W I AS8028 I -
35、 12 - BURNER DIFFERENTIAL IIIANOMETER CONNECTORS OR1 F I CE CHAIIERS FIGURE 2-1 STANDARD BURNER ASSEMBLY SAE AS*8028 80 83573LtO OU34235 T U I - 13 - I AS8028 I- 7.625 (19.37 cm) Tubes located at intersection of solid Dots locate secondary air holes lines Top plate drilled for tubes and secondary ai
36、r .125 (0.318 cm) copper tube No. 38 drill e. 7. ooa (17.78 cm) -4 (O. 318 Seal (tight fit, weld or braze, etc.) Lower plate drilled for tubes only) Four .125 (0.318 cm) pipe taps I located directly in line with center row of .125 (0.318 cm) copper tubes in each of the quadrants. Burner Base Figure
37、2- 2. Standard Burner SAE AS*8028 80 W 83573i10 00342Lb L # -_ - 14 - Standard Burner Assembly. The complete standard burner assembly is shown in Fig. 2-1. Details of the com- ponents of this assembly are given in Figs. 2-2, 2-3, and 2-4. L ,625 (1.59 cm) SECTIOH 6-6 ,500 (1.27 on) rl in. - 14 Threa
38、d Two 281 (0.71 cn) f- Hole; SECTIQI A-A Figure 2-3. Burner Base End Plate .297 (0.76 m) Hole Four .250 (0.61 ca) Holes 4- ,125 (0.32 cd 1-7/16 In. - 20 Threa Figure 2-4. Orifice Chamber Fig. 2-2 shows the details of the burner and the burner grill which consists of two plates connected by l/d-inch
39、(3.18 m) copper tubes. Gas and air are mixed in the burner base and travel upward through the tubes. The burning takes place above the top plate of the burner. Cooling air is admitted to the burner through the four 1/8-inch (3.15 mm) pipetapped holes between the plates of the burner grill. This air
40、passes upward through the No, 38 drill holes in the top plate and serves as a means for controlling the overall tempera- ture of the flame. The loction of the four 1/8-inch (3.18 mm) critical. They must be located directly in line with the center row of 1/8 inch (3.18 mm) copper tubes in each of the
41、 four quadrants, Improper location of these connections will result in an unequal radial distribution of cooling air and will affect the distribution of the flame temperature in a like manner. Fig. 2-3 shows the details of the burner base. When the two 11/32 inch (8.73 mm) diameter holes in the burn
42、er plug are drilled, care should be taken that the center line connecting these holes will be at right angles to the center line connecting the two 19164- inch (7.54 mm) diameter holes in the base. When these 11/32-inch (8.73 mm) diameter holes are properly located, the 19/64-inch (7.54 mm) diameter
43、 holes cannot be seen when one looks vertically downward into the burner base. This misalignment of holes aids in the mixing of the gas and air before they ascend to the burner grill. Fig. 2-4 shows the details of an orifice and of an orifice chamber. Three are required. Two of these orifice chamber
44、s have end plates with the 3/8-inch (9.53 mm) Parker thread fittings on both ends and are fastened directly into the burner base. The third orifice chamber has an end plate with a Parker thread fitting on one end and the plate with four 1/4 inch (6.35 m) diameter holes in the other end. This end of
45、the chamber is connected to the burner by four copper tubes, each 1/4 inch (6.35 mm) in out- side diameter (OD) and 13-1/2 inches (342.9 nml) long. One of the orifice chambers connected to the base is for measuring the gas supplied to the burner and has an orifice 5/32 (0,01625) inch (.O0671 mm) in
46、diameter. chamber connected to the base is for measuring the mixing air supplied to the burner and has an orifice 1/4 (0.25) inch (6.35 mm) diameter. The third orifice chamber connected to the burner by four 1/4-inch (6.35 mm) OD copper tubes is for measuring cooling air supplied to the burner and h
47、as an orifice 5/16 (0.3125) inch (7.9375 irun) in diameter. The gas should deliver approximately 2500 British Thermal Units (BTU) per cubic foot (9.315 x lo7 J per cubic meter). cubic feet (.736 CU m)of gas per hour for the 2500F (llOOC) flame. The flame produced should be uniform and steady with no
48、 yellow tips. The differential manometer readings of the pressure drops across the orifice should be: pipe-tapped holes is The other orifice The burner should consume 26 1. Gas orifice (5/32-inch (3.97 mm) 2. diameter, 0.99 inch (25.15 mm) of water. Mixing-air orifice (1/4-inch (6.35 m) diameter). 9
49、.25 inches (23.50 cm) of water, diameter, 11.0 inches (27.94 cm) of water. In order that the burner might produce the right amount of heat, the differential pressure for the gas and the mixing air should be accurately controlled. air may be necessary in order to obtain the proper temperature, 3. Cooling-air orifice 6/15-inch (10.16 mm) A slight variation in the cooling
