About Our Modal Exciters

The quality of an experimental modal model is directly proportional to the quality of the Frequency Response Functions measured between the chosen input locations and output locations. Contrary to what many experimentalists think, the input (force) measurement is one of the most critical aspects of a successful modal test. Errors originating here will not only effect each and every Frequency Response Function measurement, but also, the errors will typically be "hidden" and, unlike the output (vibration) measurements, difficult to detect visually.

Obtaining accurate and reliable force measurements is therefore a significant challenge where several issues have to be dealt with in the test setup. For a precision modal test setup, where one or several exciters is the natural choice of excitation, these include:

• Choosing the best exciter location
• Minimising exciter/test structure interaction
• Distributing and minimising dynamic force levels
• Ensuring sufficient low frequency energy input

Based upon years of practical modal test experiences, the line of Brüel & Kjær Modal Exciters, all exhibiting high force-to-weight ratio, has been specifically developed to address these issues and help ensure the best possible modal test performance with minimum setup time. With force ratings from 100 N to 1000 N (sine), up to 2-inch stroke capability, special "hole through" magnesium armature for tension wire stinger technology and rare earth magnet technology (some Types only), this line of robust modal exciters is ready to handle even the most demanding modal test application. The unique and optional built-in electrical stinger pre-tensioning system maintains complete freedom of exciter positioning and orientation. It allows the use of superior tension wire stinger technology without traditional external mechanical wire pre-tensioning.

A complete range of dedicated accessories is available, providing an unsurpassed high degree of measurement precision and ease of setup. This range includes force transducers, impedance heads, exciter stands for easy horizontal positioning, as well as a family of stingers. Push/pull and various tension wire types are available with different attachment methods, including a novel "snap on" accessory for fast mounting and dismounting of push/pull types of stingers.

Benefits

• Force range from 100 N to 1000 N (sine)
• Complete line of perfectly matched, heavy duty power amplifiers
• Low weight, high rigidity, precision machined magnesium moving element
• Superior force-to-weight ratio due to unique rare earth magnet technology
• Possibility to use tension wire technology
• Up to 2-inch peak-to-peak displacement for enhanced low frequency performance
• Complete line of accessories, crucial for a successful modal test – stingers (push/pull and piano wire), standard trunnions, rugged horizontal exciter stands and piano wire with electrical pre-tensioning system