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  • Watch the video of this example.

    Measuring of vibration characteristics

    Vibration characteristics help you to evaluate the condition of your machines. You can quickly assess the operating vibrations of your machines and carry out expensive maintenance only when it is really necessary. In VibroMatrix, characteristic values are displayed with the InnoMeter and their time history is drawn with the InnoPlotter.

    The measurement of vibration characteristics can be carried out according to prescribed rules. These are e.g. technical guidelines or standards. In our example, we  the standard DIN ISO 10816 "Mechanical vibration - Evaluation of machine vibration by measurements on non-rotating parts". This standard gives details of the measurement procedure and the evaluation of the results.

    • Measuring points
    • Evaluation zones

    Vibration characteristics are measured, for example on bearings or bearing housings. It is measured in each case in three mutually perpendicular directions. The largest measured value is decisive.

    The measurement is evaluated on the basis of a zone classification. For many machine classes limit values of the individual zones are specified in the standard.

    Practical example on the machine model

    Measuring chain
     

    First, the measuring chain is set up:

    • Three accelerometers are mounted on the machine to measure in three perpendicular directions.

    • The sensors are connected to the InnoBeamern and they are connected to a computer.

       

     

     

    The VibroMatrix software reproduces the measurement chain in the program. The individual measuring channels can be named according to the measuring direction.

    InnoMeter - the numerical representation of characteristic values

     

    First of all, the InnoMeter is started. A wide range of settings can be made in the opened InnoMeter. The characteristic values are kept. The filter setting depends on the standard. DIN ISO 10816 requires 10-1000 Hz. These values are entered. Acceleration, speed or displacement can be used as a measurement variable. Most commonly used is the vibration velocity with the unit mm/s. The "True RMS value" is already set and should be used.

     

    In order to measure all three channels simultaneously, the current InnoMeter only needs to be cloned twice. In the new instruments the respective signal source is adjusted.

    After starting the machine, we click on "Start all Instruments" in the InnoMaster the RMS values of all three measuring directions are immediately displayed.

    Evaluation of characterisics according to DIN ISO 10816

    According to the standard, the largest measured value is decisive. By changing the statistics function, only the maximum value is displayed. According to the standard, the limit values for small machines apply to this model machine. Based on the measured data, the machine can be assigned to zone A. Everything is in the green area, the machine can be used without limitations.

     

    The cloning function of the InnoMeter has further advantages: For example, you can monitor the characteristics of another measured quantity in a different frequency range at the same time. Here for example the peak value of the vibration acceleration from 1 - 25 kHz in the axial direction.

    • In this way, you are immediately able to gain insight according to various normative or internal requirements.

    InnoPlotter - the display of characteristic values in graph format

    If you want to view the characteristic value over time, the InnoPlotter is ideal. The setting options correspond to those of the InnoMeter. Let's take a look at the characteristic values at different speeds. To do this, the the desired parameters are selected. In practice, several channels can be displayed at the same time. All you need to do is increase the number of channels and select the signal source.

     

    The measurement starts by pressing the "Start button". For clarity the display mode is changed. The characteristic values of the individual measuring directions are now stacked on top of each other. Now the speed is slowly reduced and the change of the amplitudes can be observed.

    InnoPlotter - Change of magnitude during reduction of speed

    Vibration monitoring allows you to easily determine the operating status of your machines. This allows you to quickly identify upcoming issues.

     

    Increased vibration characteristic values indicate faults in the operation of the machine. Here a more precise vibration analysis is necessary to find out the respective cause.