The E-MISHA, a Miniature Shaker with Integrated Sensors
This miniature shaker was developed by LMS Engineering Services to do highly accurate structural excitation in a minimum of space. It provides excitation, but with extremely low mass and stiffness loading of the test-object, integrated force measurement sensors and integrated acceleration measurement sensors. All of this is realized within a sphere of only 40.5 mm.
The forces needed to use the mini-shaker are not huge, around 2.5 N RMS between 50 and 5000 Hz, but this is sufficient for the excitation of car bodies, engines, transmissions, machinery, etc. The E-MISHA is especially suitable for those who are planning to do Experimental Modal Analysis, TPA, Frequency Based Sub-structuring and experimental SEA.
It improves the efficiency of testing by eliminating all of the support and alignment work associated with shaker testing - it is self-supporting, it can be glued to the test object, no need for extra support. It is self-aligning, when the sensors are put in place - the force is aligned along the same axis.
Vibro-acoustic Transfer Path Analysis
Mostly used on engines and other machinery to investigate internal contributions and the vibro-acoustic sensitivity of the structure. Sometimes used on cars and trucks to study mid frequency structure borne sound from the engine and transmission as well as smaller equipment like ventilation units, steering mechanisms, and electro-motors. Typical instrumentation includes Scadas III : 16 channels or more, two E-MISHA’s, a large number of accelerometers and some microphones. Typical software includes F-Mon, TPA, and RMA. This mini shaker gives the user all the advantages of its small size, its fully sufficient excitation level and the edge of being able to instrument the test object quickly.
EMA, Structure Modal Analysis
Mostly used on engines and transmissions, but sometimes used on electro-motors, steering systems, and small machinery, etc. A typical instrumentation would take a Scadas III : 16 channels (or more), two miniature shakers, a large number of accelerometers and some microphones. The software typically used with for EMA, and Structure Modal Analysis is LMS F-mon, RMA, EMA, and Modal design.
Users will find the mini shaker useful because of its miniature size, its low mass and stiffness loading, its fully sufficient excitation level and the edge of being able to instrument the test object quickly.
SEA Tests
Used mostly for car and truck bodies, but sometimes used for aircraft fuselage, aircraft APU, and machinery encapsulation, etc.. Standard instrumentation includes Scadas III : 16 channels or more, two E-MISHAs, a large number of accelerometers and microphones. Typical software includes F-mon, RMA, and SEA. Advantages include fast instrumentation, highly accurate input power measurements and its miniature size.
Technical specifications
- Size, diameter: Round 40.5 mm
- Weight excluding cable: 0.15 Kg
- Effective frequency range: 50 to 5000 Hz
- Constant real-time force signal freq. range: 50 to 5000 Hz, +-1 dB
- Constant real-time acceleration signal freq. range: 50 to 5000 Hz, +-2 dB
- Output acceleration sensitivity: 1000 m/s2V nominal
- Output force signal sensitivity: 150 N/s2V nominal
- Output signal conditioning requirement: ICP
- Test object mass loading: less then 10 gram
- Test object off-axis stiffness loading: less then 10 N/mm
- Source input impedance: 10 Ohm nominal
- Required signal output impedance: 10 KOhm
- Maximum input current: limited by a F500mA fuse
- Minimal power amplifier requirement: 50 Watt and 12 Volt (RMS)
- Maximum force output***: 2. 5 N RMS
Note: Performance and dimensions of the device, as stated above, are an indication only. The actual values of the delivered product can deviate from the given specification. However, in most of such cases the specifications will exceed the given ones above, because of improvements in the used materials and design.
*** When using continuous broadband random noise 50 to 5000 Hz, of low crest factor.
Applications
Vibro-acoustic Transfer Path Analysis
Mostly used on engines and other machinery to investigate internal contributions and the vibro-acoustic sensitivity of the structure. Sometimes used on cars and trucks to study mid frequency structure borne sound from the engine and transmission as well as smaller equipment like ventilation units, steering mechanisms, and electro-motors. Typical instrumentation includes Scadas III : 16 channels or more, two E-MISHA’s, a large number of accelerometers and some microphones. Typical software includes F-Mon, TPA, and RMA.
This mini shaker gives the user all the advantages of its small size, its fully sufficient excitation level and the edge of being able to instrument the test object quickly.
EMA, Structure Modal Analysis
Mostly used on engines and transmissions, but sometimes used on electro-motors, steering systems, and small machinery, etc. A typical instrumentation would take a Scadas III : 16 channels (or more), two miniature shakers, a large number of accelerometers and some microphones. The software typically used with for EMA, and Structure Modal Analysis is LMS F-mon, RMA, EMA, and Modal design.
Users will find the mini shaker useful because of its miniature size, its low mass and stiffness loading, its fully sufficient excitation level and the edge of being able to instrument the test object quickly.
SEA Tests
Used mostly for car and truck bodies, but sometimes used for aircraft fuselage, aircraft APU, and machinery encapsulation, etc.. Standard instrumentation includes Scadas III : 16 channels or more, two E-MISHAs, a large number of accelerometers and microphones. Typical software includes F-mon, RMA, and SEA. Advantages include fast instrumentation, highly accurate input power measurements and its miniature size.
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