GB/T 11468-1989 265 Radio altimeter

This standard specifies the main performance requirements, environmental requirements, test methods and inspection rules as well as marking, packaging, transportation and storage of radio altimeters (hereinafter referred to as altimeters). GB/T 11468-1989 265 Radio altimeter GB/T11468-1989 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
GB/T11468—1989
265 Radio Altimeter
265 Radioaltimeter
1989-03-01 Issued
1990-01-01 Implementation
Issued by the Ministry of Machinery and Electronics Industry of the People's Republic of China
National Standard of the People's Republic of China
265 Radio Altimeter
265 Radioaltimeter
1 Subject Content and Scope of Application
GB/T11468—1989
This standard specifies the main performance requirements, environmental requirements, test methods and inspection rules, as well as marking, packaging, transportation and storage of 265 radio altimeter (hereinafter referred to as altimeter). This standard applies to 265 radio altimeter. 2 Reference standards
GB11469 General technical conditions for radio altimeters GB2423.22
Basic environmental test procedures and methods for electric and electronic products
Test Nb: Temperature change test with a specified temperature change rate 5 Basic environmental test procedures for electric and electronic products Test Z/AM: Low temperature/low pressure comprehensive test GB2423.25
Basic environmental test procedures for electric and electronic products Test Z/BM: High temperature/low pressure comprehensive test GB2423.26
Basic environmental test procedures for electric and electronic products Test Eb: Collision test methods GB2423.6
HB5662
Requirements and test methods for electromagnetic compatibility of aircraft equipment 3 Composition of altimeter Appearance, dimensions and mass
3.1 Composition of altimeter
The altimeter consists of a transceiver, an indicator, an antenna and a high-frequency cable. 3.2 Dimensions
Transceiver: See Figure 1.
Indicator: See Figure 2 for dynamic type and Figure 3 for servo type. Antenna: See Figure 4.
Approved by the Ministry of Machinery and Electronics Industry of the People's Republic of China on March 1, 1989 and implemented on January 1, 1990
GB/T11468—1989
Figure 1 Transceiver Dimensions
Figure 2 Moving Coil Indicator Dimensions
The mass of the transceiver shall not exceed 3.5kg.
The mass of the indicator shall not exceed 0.85kg.
The mass of the antenna shall not exceed 0.4kg.
4 Technical requirements
4.1 General requirements
4.1.1 Appearance
GB/T11468—1989
Appearance of servo-type indicator
Figure 4 Appearance of antennabzxZ.net
The appearance of the altimeter shall comply with the requirements of Article 3.1.1 of GB11469. 3
4.1.2 Working frequency
GB/T 11468—1989
The working frequency of the altimeter is 4300±10MHz. 4.1.3 Altitude resolution
Over flat ground, the resolution of the altimeter is 0.15m or 0.1% of the actual altitude. 4.1.4 Tracking speed
The tracking speed of the altimeter for the aircraft altitude shall not be less than 533m/s. 4.1.5 Flight attitude limit
When the pitch and roll angles of the aircraft are within the range of ±35°, the altimeter should not lose tracking. 4.1.6 Power supply
The power supply used by the altimeter is:
DC 27V±10%, current less than 2A.
AC 115V±5%, 400Hz±5%, power consumption does not exceed 27V·A. 4.2 Main performance requirements
4.2.1 Connection and insulation resistance
The connection resistance between the B, D, T, V, and W points of the transceiver socket CZ1o and the housing should not be greater than 0.52. The connection resistance between the L point of the indicator socket CZ and the housing should not be greater than 0.5Q, and the insulation resistance between the A, F, Y, a, b, and f points of the moving coil indicator CZ and the housing should not be less than 20MQ. The insulation resistance between the inner and outer conductors of the antenna coaxial socket should not be less than 20MQ. 4.2.2 Startup time
The time from power on to entering the tracking state is the start-up time. The start-up time of the altimeter should be 30±15s. 4.2.3 Sensitivity
4.2.3.1 Total sensitivity
The altimeter should be able to stably measure altitude in the range of 0~1500m above various ground surfaces such as farmland, water surface, forest, grassland, desert, etc. The locking altitude and unlocking altitude should both be greater than 1500m. Note: When the flight altitude exceeds the altimeter's altitude measurement range (1500m), the output altitude signal is locked at a fixed value, and the indicator pointer is locked in the dark area of ​​the dial, which is called the locked state. When the locked state is switched to the normal altitude measurement state, it is called unlocking. 4.2.3.2 Zero altitude sensitivity
a. When the equivalent altitude is 0m, the search sensitivity of the altimeter is 78±4dB; the tracking sensitivity is 76±4dB; b. When the equivalent altitude is 0m, the voltage change of the output altitude signal I should not be greater than 40mV when the signal strength of the external loop changes from 52dB to 76dB,
c. When the altimeter switches from tracking-searching-tracking, the output altitude signal I should not have a pulse peak greater than 3m-s; Note: A pulse peak of 3m-s is equivalent to a voltage amplitude of 3m altitude, with a duration of 1s, or a voltage amplitude of 3m altitude and a duration of 0.1s. d. When the equivalent altitude is 0m, the voltage of the output altitude signal I should be 0±0.04V, and the indicator should point to about 0m. 4.2.3.3 High altitude sensitivity
When the equivalent altitude is 418m and the attenuation of the outer loop is 116dB, the output altitude signal voltage is: output altitude I: -10.965±0.500V; output altitude I: 5.4800.250V.
The indicator should point to about 420m, and the search sensitivity should not be less than 127dB. 4.2.4 Altitude measurement accuracy
4.2.4.1 Total altitude measurement accuracy
The total altitude measurement accuracy of the altimeter is the comparison of its output altitude signal with the actual altitude value, which should meet the following requirements: Output altitude I (linear signal 0~-40V) is: ±0.91m or 3% of the actual altitude.
Output altitude I (linear signal 020V) is: GB/T11468-1989
0~30m±(1.21m+1% of actual altitude);301500m±(0.3m+4% of actual altitude). 4.2.4.2
Simulated altitude accuracy
The simulated altitude accuracy of the altimeter shall comply with the provisions of Table 1. Table 1
Simulated altitude
Indicator accuracy
Loop attenuation
100±2
100±2
100±2
Simulated altitude accuracy
Output altitude I, V
Rated value
—40.000
The accuracy of the moving coil indicator shall comply with the provisions of Table 2 4.2.5.1
Table 2 Accuracy range of moving coil indicator
0 (adjustable)
Input signal
The accuracy of the servo indicator shall comply with the provisions of Table 3 and Table 4. Output altitude, V
Rated value
0 (adjustable)
Altitude warning range and warning accuracy
Selected.
GB/T11468—1989
3Accuracy range of servo-type indicator I
Input signal
4Accuracy range of servo-type indicator I
Input signal
The altitude warning range is 01500m.
The altitude point of the warning can be adjusted continuously in the whole range by using the preset cursor. The alarm accuracy of any moving coil indicator: When the altitude pointer points to the altitude set by the preset cursor and is lower than this altitude, the alarm light should be on, and the difference between the altitude voltage value at the beginning of the alarm and the actual value measured according to Table 2 of Article 4.2.5.1 should meet the requirements of Table 5. Table 5 Alarm accuracy of moving coil indicator
Alarm accuracy of servo indicator: When the altitude pointer reaches about 30m above the altitude set by the preset cursor, an alarm sound is issued. As the pointer approaches the cursor, the sound increases from weak to strong. When it reaches the alarm point, the sound is the loudest and disappears immediately. At the same time, the alarm light comes on. The difference between the altitude signal value at this time and the actual value measured according to Table 3 and Table 4 of Article 4.2.5.2 shall comply with the provisions of Table 6 and Table 7. 6
4.2.7 Locking state
GB/T11468—1989
Table 6 Servo-type indicator warning accuracy I
Table 7 Servo-type indicator warning accuracy I
When the altimeter loses tracking, the voltage of the output altitude signal I should be -46±0.7V, the voltage of the altitude signal I should not be less than 22.5V, and the output validity signal should be 0V. At the same time, the pointer of the indicator should deflect to the dark area above 1500m, and a warning flag should appear on the indicator.
4.2.8 Reference voltage
In the tracking state, the reference voltage should be -50±0.25V and 25±0.20V. 4.2.9 Self-test
When the self-test button switch is pressed, the voltage of the output altitude signal I is -0.80±0.08V, the indicator should point to around 30m, and the a and L points of the indicator socket CZ should be connected. After releasing the self-test button switch, the a and L points of the indicator socket CZ should be disconnected. 4.2.10 Power interruption
In the tracking state, when the AC 115V power supply is interrupted for 50ms, the altimeter should not lose tracking. 4.2.11 Power supply change
When the DC 27V power supply voltage changes to 16V and 32V respectively, the altimeter in the tracking state should not lose tracking. When the AC 115V power supply voltage changes to 103V and 127V respectively, the indicator should meet the requirements of Articles 4.2.5 and 4.2.6. 4.2.12 Antenna standing wave ratio
In the frequency range of 4274~4325MHz, the voltage standing wave ratio of the antenna should not be greater than 18. 4.2.13 Antenna gain
At the frequency of 4300MHz, the antenna gain should not be less than 10.5dB. 4.2.14 Antenna Directivity
At a frequency of 4300MHz, the antenna directivity shall meet the requirements of Figures 5 and 6, and the half-power beam width shall not be less than 40°4.2.15 Antenna Isolation
At a frequency of 4300MHz, when installed according to Figure 7, the isolation between the two antennas shall not be less than 85dB. 7
GB/T11468—1989
###電#77777
Figure 5H Plane Directivity
GB/T11468—1989
Figure 6E Plane Directivity
4.2.16 Reliability
GB/T11468—1989
Figure 7 Antenna Installation Diagram during Isolation Test
The mean time between failures (MTBF) of the altimeter is 300h. 4.3 Environmental requirements
4.3.1 Temperature variation
The transceiver should be able to operate normally during the temperature variation of -55 to +55°C. The indicator should be able to operate normally during the temperature variation of -30 to +70°C, and not be damaged in the extreme temperature variation of -55 to +85°C. The antenna should not be damaged in the extreme temperature variation of -65 to +120°C. 4.3.2 Temperature-altitude
The transceiver should be able to operate normally in the environment of temperature of -55°C and air pressure of 7.5kPa (18050m) and temperature of +55°C and air pressure of 12kPa (15070m), and can operate for a short time under the extreme conditions of temperature of -55°C and air pressure of 2.5kPa (25000m).
The indicator should be able to work normally in an environment with a temperature of -25℃ and an air pressure of 25kPa (10400m) and a temperature of +40℃ and an air pressure of 2.5kPa.
The antenna should be able to work normally in an environment with a temperature of -55℃ and an air pressure of 2.5kPa (25000m) and a temperature of +120℃ and an air pressure of 2.5kPa.
4.3.3 Alternating damp heat
The altimeter should be able to work normally in an alternating damp heat environment with a temperature of +20～35℃ and a relative humidity of not less than 95%. 4.3.4 Vibration
The altimeter should be subjected to a 101000Hz sine sweep vibration test in three axial directions for a total of 50h, and the vibration intensity should meet the requirements of Figure 8. It should be able to work normally during vibration and keep the structure intact. If there is resonance, the initial resonance point and the final resonance point should be consistent. 10
4.3.5 Collision
GB/T11468—1989
Position=+1,
Statement=:+m
Figure 8 Vibration intensity curve
The transceiver shall withstand 4000 collision tests with an acceleration of 400m/s2, a half-sine wave pulse width of 6ms, and a frequency of 1~3Hz, and keep the structure intact and work normally.
4.3.6 Constant acceleration
The altimeter shall withstand the constant acceleration test specified in Table 8, and shall be able to work normally and have an intact structure during the performance test; during the structural test, the time for each acceleration test is 10s.
The specimen shall not fall off the fixture, and abnormal operation is allowed after the test. Table 8 Constant acceleration test strength
Test category
Performance test
Structural test
4.3.7 Fungus
Test unit
Transceiver
Indicator
Transceiver
Indicator
Altimeter shall meet the requirements of Article 3.3.6 of GB11469. 4.3.8 Salt spray
Altimeter shall meet the requirements of Article 3.3.7 of GB11469. 4.3.9 Acoustic vibration
—250
Altimeter transceiver shall meet the requirements of Article 3.3.8 of GB11469. 4.3.10 Magnetic influence
Altimeter shall meet the requirements of Article 3.6 of GB11469. 4.3.11 Electromagnetic compatibility
From the acceleration
The altimeter shall comply with the provisions of 3, 5, 7, 8, 9, 13 and 14 of Class IA in Table I of HB5662. 2
4.3.11.1 The altimeter is connected to a delay line with an equivalent height of 21m, and its conducted interference and radiated interference are measured in the tracking, search and self-test states.
4.3.11.2 During the sensitivity test of the altimeter, the change of its output altitude signal in the tracking state shall not exceed ±1m; in the search state, the interference signal shall not be tracked.2 Temperature-Altitude
The transceiver should be able to work normally in an environment with a temperature of -55°C and an air pressure of 7.5kPa (18050m) and a temperature of +55°C and an air pressure of 12kPa (15070m), and can work for a short time under the extreme conditions of a temperature of -55°C and an air pressure of 2.5kPa (25000m).
The indicator should be able to work normally in an environment with a temperature of -25°C and an air pressure of 25kPa (10400m) and a temperature of +40°C and an air pressure of 2.5kPa.
The antenna should be able to work normally in an environment with a temperature of -55°C and an air pressure of 2.5kPa (25000m) and a temperature of +120°C and an air pressure of 2.5kPa.
4.3.3 Alternating damp heat
The altimeter should be able to work normally in an alternating damp heat environment with a temperature of +20～35℃ and a relative humidity of not less than 95%. 4.3.4 Vibration
The altimeter should be subjected to a 101000Hz sine sweep vibration test in three axial directions for a total of 50 hours, and the vibration intensity should meet the requirements of Figure 8. It should be able to work normally during vibration and keep the structure intact. If there is resonance, the initial resonance point and the final resonance point should be consistent. 10
4.3.5 Collision
GB/T11468—1989
Position=+1,
Statement=:+m
Figure 8 Vibration intensity curve
The transceiver shall withstand 4000 collision tests with an acceleration of 400m/s2, a half-sine wave pulse width of 6ms, and a frequency of 1~3Hz, and keep the structure intact and work normally.
4.3.6 Constant acceleration
The altimeter shall withstand the constant acceleration test specified in Table 8, and shall be able to work normally and have an intact structure during the performance test; during the structural test, the time for each acceleration test is 10s.
The specimen shall not fall off the fixture, and abnormal operation is allowed after the test. Table 8 Constant acceleration test strength
Test category
Performance test
Structural test
4.3.7 Fungus
Test unit
Transceiver
Indicator
Transceiver
Indicator
Altimeter shall meet the requirements of Article 3.3.6 of GB11469. 4.3.8 Salt spray
Altimeter shall meet the requirements of Article 3.3.7 of GB11469. 4.3.9 Acoustic vibration
—250
Altimeter transceiver shall meet the requirements of Article 3.3.8 of GB11469. 4.3.10 Magnetic influence
Altimeter shall meet the requirements of Article 3.6 of GB11469. 4.3.11 Electromagnetic compatibility
From the acceleration
The altimeter shall comply with the provisions of 3, 5, 7, 8, 9, 13 and 14 of Class IA in Table I of HB5662. 2
4.3.11.1 The altimeter is connected to a delay line with an equivalent height of 21m, and its conducted interference and radiated interference are measured in the tracking, search and self-test states.
4.3.11.2 During the sensitivity test of the altimeter, the change of its output altitude signal in the tracking state shall not exceed ±1m; in the search state, the interference signal shall not be tracked.2 Temperature-Altitude
The transceiver should be able to work normally in an environment with a temperature of -55°C and an air pressure of 7.5kPa (18050m) and a temperature of +55°C and an air pressure of 12kPa (15070m), and can work for a short time under the extreme conditions of a temperature of -55°C and an air pressure of 2.5kPa (25000m).
The indicator should be able to work normally in an environment with a temperature of -25°C and an air pressure of 25kPa (10400m) and a temperature of +40°C and an air pressure of 2.5kPa.
The antenna should be able to work normally in an environment with a temperature of -55°C and an air pressure of 2.5kPa (25000m) and a temperature of +120°C and an air pressure of 2.5kPa.
4.3.3 Alternating damp heat
The altimeter should be able to work normally in an alternating damp heat environment with a temperature of +20～35℃ and a relative humidity of not less than 95%. 4.3.4 Vibration
The altimeter should be subjected to a 101000Hz sine sweep vibration test in three axial directions for a total of 50 hours, and the vibration intensity should meet the requirements of Figure 8. It should be able to work normally during vibration and keep the structure intact. If there is resonance, the initial resonance point and the final resonance point should be consistent. 10
4.3.5 Collision
GB/T11468—1989
Position=+1,
Statement=:+m
Figure 8 Vibration intensity curve
The transceiver shall withstand 4000 collision tests with an acceleration of 400m/s2, a half-sine wave pulse width of 6ms, and a frequency of 1~3Hz, and keep the structure intact and work normally.
4.3.6 Constant acceleration
The altimeter shall withstand the constant acceleration test specified in Table 8, and shall be able to work normally and have an intact structure during the performance test; during the structural test, the time for each acceleration test is 10s.
The specimen shall not fall off the fixture, and abnormal operation is allowed after the test. Table 8 Constant acceleration test strength
Test category
Performance test
Structural test
4.3.7 Fungus
Test unit
Transceiver
Indicator
Transceiver
Indicator
Altimeter shall meet the requirements of Article 3.3.6 of GB11469. 4.3.8 Salt spray
Altimeter shall meet the requirements of Article 3.3.7 of GB11469. 4.3.9 Acoustic vibration
—250
Altimeter transceiver shall meet the requirements of Article 3.3.8 of GB11469. 4.3.10 Magnetic influence
Altimeter shall meet the requirements of Article 3.6 of GB11469. 4.3.11 Electromagnetic compatibility
From the acceleration
The altimeter shall comply with the provisions of 3, 5, 7, 8, 9, 13 and 14 of Class IA in Table I of HB5662. 2
4.3.11.1 The altimeter is connected to a delay line with an equivalent height of 21m, and its conducted interference and radiated interference are measured in the tracking, search and self-test states.
4.3.11.2 During the sensitivity test of the altimeter, the change of its output altitude signal in the tracking state shall not exceed ±1m; in the search state, the interference signal shall not be tracked.
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