Et teid paremini teenindada, siis kasutame küpsiseid. Kasutamist jätkates nõustute küpsiste ja veebilehe üldtingimustega. Lisateave.
PMM 10/2.9 Pneumatic telescope mast 10m
These masts are made of concentric sections of anodized aluminium, equipped with a lock against rotation. The top section is terminated with a large flange which allows installation of various payloads. The fucntional principle is the reverse of an air pump for your bicycle: if you put pressurised air into the nozzle of the pump, the handle extends due to the internal pressure.
The compressor required to extend the mast is not included in shipment; but you can use any other existing compressor our source of pressurized air as well (e.g. the pressurized air of a truck brake).
The mast is operated (extended or lowered) by a three-position valve: Raise/Hold/Lower.
When one section of the mast is fully extended it locks into the next section. This locking ensures that the mast is held extended even when the pressurised air is removed. The mast can even be locked in different heights by not extending all sections. To lower the mast just pull the release handle on the lowest section, the uppersections will lower themselves gently. Then pull the handle of the next section ow in reach, lower this, and so on...
For installation on level surfaces the mast comes equipped with a solid tripod. This tripod allows adjustments for slopes with some inclination. This tripod must be fixed to ground, even for masts marked as "self supporting, no guying required". Alternatively mast clamps for installation on a wall or vehicle are available.
We offer three different models.
PMM 9/2.8 is intended at stationary deployment for operation with guying. Maximum allowable wind load can not be specified because it depends on the guying. It is also possible to operate the mast self-supporting, however maximum top load and antenna surface are not specified.
PMM 6/2.3 can be operated guyed or self-supporting, but a static calculation is not available. PMM 10/2.9 can be used as a reference point - pipe diameter of the top three pipes are identical.
Static calculations for wind zones 1 and 3 are available for the PMM 10/2.9, see below.
The table details the PMM 10/2.9 apply for free-standing operation, with the mast with the antenna surface and 120km/h calculated approximately 66cm bends. Therefore it is recommended also to guy the mast, and of course the antenna surface can be enlarged when operating with guying wires. When the center of the antenna surface is in the amount of the guying point so that no torque is exerted by the wind, the maximum antenna surface would be theoretically infinite. But please do not overload, because the mast otherwise be bulgy and can break, especially when the bias of the guying wires are to strong. Because the force applied by the guying tension is indeed in relation to the tension angle as a compressive force in the mast!