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The installation at the Hermann Monument
Finally, on July 2, 2012, the lightning monitoring device LM-S was installed on the Hermann Monument.
In order to attach the three sensors at a height of 30 meters (just below the actual copper statue) to the external lightning conductors, an elevating truck was required. With the help of the truck’s 50 m long swivel arm, the sensors and the fiber optics could be attached and connected. At the same time, a control cabinet housing the corresponding electronics was mounted onto the monument’s stone base.
The actual lightning monitoring system was furthermore equipped with a mobile radio modem allowing the readout of results at any time. Ever since that time, every lightning strike which directly hits the Hermann Monument will be recorded. The results can be seen on this Internet page. -
Why the Hermann?
Since the Hermann Monument overlooks the Egge mountains, it cannot only be seen even from a large distance, it is also a good target for lightning strikes. The held up sword functions like a lightning rod.
The area about a square kilometer in size around the monument is hit by an average of 5 lightning strikes per year. According to the statistics, there are only 3.7 lightning strikes per year and square kilometer in Germany in total. Thus, the Hermann Monument is also statistically, an excellent place to measure and study lightning currents.
In contrast to the industry, it is not the foremost target to detect potential damages at the system at an early stage. The recording of lightning strikes serves to statistically evaluate lightning events and their strength. Such applications are of particular interest for lightning research.
More detailed and further
information can be found at the following link.
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Where are the sensors attached?
Entrance area Outside stairs Inside stairs LM-S Sensors External lightning arresters LM-S evaluation unit When walking towards the entrance of the Hermann Monument, two of the lightning current sensors can be seen. The third sensor is located just on the opposite side of the entrance. You have to look very closely to recognize the sensors from below. The sensors are positioned just below the actual copper statue.
The electronics for analyzing the lightning data is installed inside the monument and consequently not visible. -
The measuring method of the lightning monitoring system is based on the
Faraday effect.Structure of the measuring system
The LM-S lightning monitoring system recognizes and analyzes all important parameters of lightning surge currents. The analysis is done in real-time.
The sensors of the measuring system are mounted on the arresters routing the lightning current. Due to the surge current, a magnet field is generated around the arrester that can be measured by the sensors. Via the fiber optics, the system then transmits the measurement results to the evaluation unit where the light waves are converted into electrical signals.
Using the obtained values, the evaluation unit determines the following parameters of the lightning characteristics:- Max. lightning current strength
- Max. lightning current slope
- Charge
- Specific energy
More detailed and further
information can be found at the following link.
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Areas of application
The system is mainly used in the industry. Exposed wind power stations like offshore wind farms, for example, are considered to be particularly at the risk from lightning. As regards such systems, the implementation of a complete and overall lightning protection measure is basically very difficult to realize, if not impossible. In such cases, the lightning monitoring system is used. If a wind power station is hit by lightning, the data can be used to estimate whether the system requires a more thorough check.
Direct lightning strikes into power lines lead to additional burden on transformers in substations. Often, surge protection elements are connected upstream to the transformers with which the surge currents from coupled surge voltages can be conducted to the ground. In the past, spark gaps were primarily used as protection elements. For a few years now, varistors are applied with preference. The LM-S offers the opportunity to record and analyze the actual load of the protection elements.
Further areas of application:- Buildings
- Telecommunication technology
- Traffic engineering