M R V C o m m u n i c a t i o n s , I n c . – I n s t a l l a t i o n M a n u a l
APPENDIXF Effect of Wind on Terescopes
Introduction
The outdoor environment in which our devices are normally placed exposes the link to wind pressures that may affect the accuracy of the link’s alignment.
Several factors play a role in the determination of the extent to which the directionality of a TS device may be affected by the wind:
Wind speed Wind direction
Surface area of device perpendicular to wind Mechanical stability of aiming head – device system.
For example, the mechanical stability is greatest along the
–even at very high wind speeds – will barely have an impact on the beam’s direction, due to the rigid mechanics along the
Wind Limits for TS Devices
All TS devices have been tested in
From here1, the minimum wind speed with maximum effect on beam deviation was determined.
The following table lists the minimum wind speeds for different TS products that may cause:
A momentary lapse in the communication.
An extended lapse requiring mechanical repair.
| TS Device | Momentary |
| Extended |
• | 10” (E&F models) | 110 km/hr |
| 200 km/hr |
• | 10” with | Over 180 km/hr |
| Over 250 km/hr |
| Accessory |
| ||
|
|
|
| |
• 4” (B,C, D models) | 150 km/hr |
| Over 250 km/hr | |
• | 4” with | 220 km/hr |
| Over 300 km/hr |
• | Light (A&C2 models) | 150 km/hr |
| Over 250 km/hr |
• | PAL (TS1) | 180 km/hr |
| Over 250 km/hr |
• 8” (Models D2, E2, G) |
| 150 km/hr | ||
1We include here the formula for calculating the effective wind force on a flat surface, given a known wind speed:
Wind Force = 0.79 x (Wind Speed)2 x (Area of Surface)
For instance, assuming a wind speed of 27.78 m/s (equal to 100Km/hr) on a surface area of 0.04m2 (400cm2), the force is equal to 24.4 Newtons.
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