Description
Attributes and Designation from Description and Usage
Quote by Description and Usage:
"The dust- and waterproof EDF 7x40 oB is destined for usage under hamepred climatic conditions of field deployment."
- Roof Prism Design
- Individually Focusing Oculars
- Spectacle Wearers Oculars
- Metal Housing
- Strong Rubber Armouring
- Down-foldable Rubber Eye Cups
- Waterproof and Dustproof
- Shock Proof
- Reticle
- Infrarotaufklärungshilfe
Specifications from Description and Usage
- Magnification 7-times
- Entry Pupil Diameter 40 mm
- Exit Pupil Diameter 5.7 mm
- Eye Relief > 20 mm
- Field of Vision on 1000 m 7° 30´ o. 131 m
- Gloaming Index 32.65
- Gloaming Rate 16.7
- Dioptrien Adjustment +- 7 dpt
- Pupillary Distance Setting < 60-75 mm
- Weight 1000 g
The rotational tests at the periodical reconditioning are very interesting.
Test conditions in extracts from "A 050/1/501 Einheitsdoppelfernrohr 7x40 reconditioning" from 1982
- Leak tightness
Over pressure test: Pressure inside 50,7 kPa (this means low head 5 m)
Specification: Pressure drop not allowed
- Low head test
Low head: 1 m
Water temperature: 10 - 15 °C lower than unit temperature (this means underpressure inside the unit)
Check-out time: 1 h
Specification: No water nor fog inside
- Drop test
Drop height: 0,75 m
Direction: 1 drop straight horizontal on broadside
- Hit test
Acceleration: 15 g
Pulse duration: 5 - 10 ms
Direction: 250 hits vertical on objective, 150 hits straight horizontal on broadside, 150 hits straight horizontal on narrow side
- Hit test
Acceleration: 120 g
Pulse duration: 1 - 5 ms
Direction: 2 hits vertical on objective, 4 hits straight horizontal on broadside, 4 hits straight horizontal on narrow side
- Vibration stress
Frequency range: 30 - 80 Hz
Acceleration: 6 g
Check-out time: 2 h vertical on objective side, 1 h straight horizontal on broadside, 1 h straight horizontal on narrow side
- Cold resistance
-50 °C, Check-out time 2 h, after unit equalization of requested temperature, rubber parts to -40 °C
- Heat resistance
+60 °C, Check-out time 2 h, after unit equalization of requested temperature
Specification: No loss of grease
- Cyclic temperature test
Upper temperature: +60 °C
Lower temperature: -50 °C
Check-out time: 5 cycle every 2 h
Specification: No loss of grease
- Storage temperature
+80 °C, Check-out time 1 h, after unit equalization of requested temperature
Specification: No loss of grease
- Sea water resistance
Temperature: +27 °C
Check-out time: 168 h
Compounding: sodium chloride 27 g/l, magnesium chloride 6 g/l, calcium chlorid (free of water) 1 g/l, potassium chlorid 1 g/l
Specification: No corrosion