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MMF VC120 Instruction Manual

Vibration calibrating system
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Instruction Manual
Vibration
Calibrating
System
VC120
Manfred Weber
Metra Mess- und Frequenztechnik in Radebeul e.K.
Meissner Str. 58 - D-01445 Radebeul
Phone. +49-351 836 2191 Fax +49-351 836 2940
Email:
Info@MMF.de
Internet:
www.MMF.de

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  • Page 1 Instruction Manual Vibration Calibrating System VC120 Manfred Weber Metra Mess- und Frequenztechnik in Radebeul e.K. Meissner Str. 58 - D-01445 Radebeul Phone. +49-351 836 2191 Fax +49-351 836 2940 Email: Info@MMF.de Internet: www.MMF.de...
  • Page 2 Metra Mess- und Frequenztechnik in Radebeul e.K. Meißner Str. 58 D-01445 Radebeul Phone 0351-836 2191 0351-836 2940 Email Info@MMF.de Internet www.MMF.de Notice: The latest version of this document can be downloaded as PDF from https://mmf.de/en/product_literature Specifications subject to change without prior notice.

  • Page 3: Table Of Contents

    Contents 1.The Instrument at a Glance..................3 2.Functions........................4 3.Mounting of Test Object..................5 4.Operation of the VC120..................7 4.1.Switching the Unit On and Off................7 4.2.Basic Settings....................7 4.3.Calibration.....................10 4.3.1.Manual Calibration................11 4.3.2.Calibration at Fixed Frequencies............12 4.3.3.Frequency Response Measurement............13 4.3.4.Calibration Errors and Their Reasons............16 4.4.Saving Measuring Results................17 4.5.Retrieval of Stored Data................18...
  • Page 4 6.4.First Connection with the PC................41 7.Power Supply.......................42 8.Transport and Maintenance..................44 9.Technical Data......................45 Appendix: Warranty CE Declaration...

  • Page 5: The Instrument At A Glance

    160 Hz coarse Menu Shaker off related keys manual MENU Battery LED SHAKER POWER On/Off button ON/OFF Shuttle wheel VC120 Vibration Calibrator Rear panel connectors: Charge Serial Sensor socket PC interface socket DC SUPPLY INPUT Mini-B 14 .. 16 V 141010 Metra Mess- und Frequenztechnik in Radebeul e.K.

  • Page 6: Functions

    We are glad about your decision to work with our Vibration Calibrating System VC120. This instrument can be easily operated by means of its self-explaining dis- play. Nevertheless, you should spend some time to read this manual. This way you will be ensured to use all functions of the instrument in the best possible manner.

  • Page 7: Mounting Of Test Object

    At lower frequencies a strong permanent clamping magnet may be used for mount- ing. The shaker head therefore consists of magnetic steel.  Do not drop the magnet onto the shaker head to protect the VC120 and the sensor from shock acceleration. Gently slide the sensor with the magnet to the place.
  • Page 8 VC120 shaker head as well as at the sensor under test. The surface of the shaker head of VC120 is flat grinded. If it shows scratches after intensive use please send the instrument back to the man- ufacturer for revision.

  • Page 9: Operation Of The Vc120

    PC software. For field use or cases where no PC is at hand, it may be useful to study this chapter. 4.1. Switching the Unit On and Off Press the SHAKER ON/OFF key about 1 s to switch on the VC120. The instru- ment now runs a self test and then displays the operation screen. Button F1...
  • Page 10 To confirm your choice press F1 (the display indicates OK). Leave the menu by pressing F1 again (the display indicates ESC). The VC120 works in all operation modes with a constant acceleration of 1 m/s² (RMS). Nevertheless, the instrument can be used not only for calibration of acceler - ometers, but also for calibration of velocity and displacement transducers.
  • Page 11 Occasionally accelerometers are not calibrated in the SI standard unit m/s², but in units of g (gravitational constant, 1g = 9.807 m/s²). The VC120 may display acceler- ation in g, although it still calibrates at 1 m/s². Switch to g display in the right field of the menu bar (MENU).

  • Page 12: Calibration

    Confirm the selection by pressing F2 again (the screen displays OK) and leave the menu by pressing F1 three times (the screen displays ESC). After finishing all basic settings of the VC120 you can start now with calibration. 4.3. Calibration After the specimen has been mounted and connected and all basic settings have been completed, you can start with calibration.

  • Page 13: Manual Calibration

    Now you can adjust the frequency by the shuttle wheel. The frequency is indicated in the upper line of the display. The VC120 offers two modes of tuning: fine and coarse. Switch from one to the other mode by pressing F1.

  • Page 14: Calibration At Fixed Frequencies

    Sometimes it is advisable to calibrate a sensor at more than one frequency. For this purpose a table of up to 10 frequencies can be stored in the VC120. Switch from one to the other frequency using the shuttle wheel.

  • Page 15: Frequency Response Measurement

    70 Hz and 10 000 Hz. This covers the lin- ear frequency range of most vibration transducers. Measured data will be down- loaded from the VC120 via the serial interface to a PC and visualized by the in- cluded software (see chapter Fehler: Verweis nicht gefunden). Frequency sweep dia- grams cannot be displayed by the VC120 itself.
  • Page 16 Figure 15: Frequency response settings Select the position to be edited by the shuttle wheel and press SEL (F2). Select the value or option using the shuttle wheel. Press F2 when the required value or option is indicated (display: OK). Now other frequency response settings can be made.
  • Page 17 high density low density flip Figure 16: Increasing the density of frequencies Exit the menu by pressing F1 three times (display: ESC). After all adjustments have been completed, you can start frequency response meas- urement. To activate the frequency response mode select in the menu (F2) the third field from the left (shuttle wheel and F2), choose the function sweep and confirm with F1.

  • Page 18: Calibration Errors And Their Reasons

    Stable condition of the sensor signal is checked permanently by the reference and measur- ing circuit of the VC120. Over a time interval of 200 ms 30 values are measured and aver- aged. If the standard deviation becomes higher than 0.5 % the instrument will show no res- ult.

  • Page 19: Saving Measuring Results

    4.4. Saving Measuring Results The VC120 features an internal memory for calibration results. Stored data can be downloaded later to a computer for archiving. The VC120 can store up to 100 re - cords. The following parameters are stored in a record: ·...

  • Page 20: Retrieval Of Stored Data

    As described in the previous chapter all measured calibrating results can be stored in the internal memory of the VC120. For retrieval of the stored data the instrument has a view function. To enter this mode activate the menu by the F2 key. Mark the third field from the left side by the shuttle wheel and confirm this by pressing F2 again.

  • Page 21: Distortion Calibration

    VC120 until the SHAKER ON/OFF button is pressed. last: The vibration exciter will work immediately and measurement will start with the last settings when the VC120 is switched on. The frequency is the same as before last switching off.

  • Page 22: Autoranging

    The measuring channel is usually operated in the autoranging mode. This way the VC120 will always process the sensor signal with the optimum resolution. It is pos- sible, however, to switch off the autoranging function. For this purpose, enter the sub-menu Signal Cond.

  • Page 23: Pc Software Vc1Xxcdb

    5. PC software VC1xxCDB The PC software VC1xxCDB (Calibration Data Base) is used to control the VC120 and to manage the calibration data in a local data base. With the help of this software it is possible to design calibration templates to auto - mate calibration cycles and to generate calibration reports automatically.
  • Page 24 The VC120 Vibration Calibrator (for which the driver is not installed automatic- ally) will be displayed below the Other Devices node. To install the driver manually click on VC120 Vibration Calibrator, and use right- click to open the context menu and left-click to select Update Driver Software.
  • Page 25 Figure 30: Update driver software Select the directory containing the USB-Driver. The default path is: C:\Program Files (x86)\Metra Radebeul\VC1xxCDB\Resources\USB-Driver Press Continue to install the USB Driver. Figure 31: Driver installation successful The USB Driver has now been successfully installed and the device can now be used.

  • Page 26: First Steps

    To finish the password entry press OK or Enter. If you have already connected the VC120 to the computer, it will switch on auto - matically. A message box appears that the software is currently not unlocked for...

  • Page 27: Unlock Device

    5.2. Unlock Device You need a software licence key to unlock the software to use all functions. You have already purchased the licence key together with the VC120 calibrator. You can find the key in the software licence document of the VC1xxCDB.

  • Page 28: First Steps

    5.3. First steps 5.3.1. The main window After you have started the program the VC120 is switched on automatically and its current parameter set is transferred to the software. The device settings always appear in the Devices tab on the right-hand side of the main window.

  • Page 29: Starting The Help Function

    In the lower half of the Device Control Panel you can see the basic device settings like Input, Quantity, Gain, Accuracy, Unit and Autostart. By clicking the buttons Start acquisition or Start Sweep the shaker of the VC120 starts for manual measurement (see chapter 5.3.3).

  • Page 30: Manual Mode

    Please click the button Stop acquisition to finish the manual measure- ment. If the display indicates unstable signal the accuracy level of the VC120 can be re- duced. Click in the field Accuracy and change it to LOW (see chapter 4.3.4). For reliable calibration results select the High option.

  • Page 31: Sensor Calibration

    5.4. Sensor Calibration Beside manual measurement sensors can also be calibrated with the help of the date- base. In this case the calibration is done automatically according to the settings of the chosen Calibration Template. The calibration results will be stored in the data base and can be compared with previous or reference calibrations of the same Sensor Type.

  • Page 32: Creating A Calibration Template

    5.4.2. Creating a Calibration Template Furthermore a Calibration Template needs to be created describing the calibration process. To do this first click in the Main Menu on Settings / Calibration Tem- plates and then on the icon to create a new calibration template. Figure 44: Calibration Template The following measuring values can be defined: •...
  • Page 33 Figure 45: Add a new sensor Before starting the measurements you have to enter the Sensor Type and the Serial number in the data fields of the mask. If you are calibrating a sensor for the first time you must also define the Calibra- tion Template used to calibrate this sensor.

  • Page 34: The Sensor View

    message Done! appears if the result is inside the tolerance range. Otherwise a red coloured message Failed! appears behind the result. The results of the Last calibration are shown on the upper right-hand side for com- parison. The diagram below shows either the result of the Sweep or the Fix Frequency measurement.

  • Page 35: Creating A Calibration Report

    The data of the selected sensors is shown below the table using four tabs: Details, Trend Chart, Frequency Response and All Measurements. The tab Details contains the results of the last sensor calibration, the used calibra- tion template as well as the customer to whom the sensor belongs. There are three buttons in the panel of the tab.
  • Page 36 Finally you can print port the calibration report by clicking on the icons of the pre- view. Figure 49: Single Protocol Detailed information can be found in the program documentation using the Help function (see Section 5.3.2).

  • Page 37: Interface Protocol

    6. Interface Protocol The VC120 can be linked to other test and control equipment by means of its stand - ardized hardware protocol for serial interfaces. Customized control software can be created in a simple way and may be used instead of the supplied PC software.

  • Page 38: Instructions Without Data Return

    Data acquisition finished The acknowledgments !START=x and !END are also sent if the data acquisition of the VC120 is started or stopped. Therefore they can be used as start / stop signal for PC data processing. 6.2. Instructions Without Data Return The following instructions do not request data from the VC120.
  • Page 39 Selects the limit for calibration error check. Identifier: Parameter range: x=[0..1] x=0: High x=1: Low SET_P Set Power On Autostart Defines the condition of the shaker after switching on the VC120. Identifier: Parameter range: x=[0..2] x=0: off x=1: last x=2: F0...
  • Page 40 SET_Q Set Quantity Vibration quantity of measuring channel. Identifier: Parameter range: x=[0..3] x=0: Acceleration x=1: Velocity x=2: Displacement x=3: IEPE bias voltage SET_S Set Sweep Settings for frequency sweep measurement . The identifier is followed by up to 5 parameters, separated by semi- colons Identifier: Sf1;f2;Inc;Po;f3...

  • Page 41: Instructions For Data Acquisition

    Each second a value is measured and saved in the internal VC120 memory. This memory serves as data buffer between the VC120 and the PC. It can hold up to 49 values. The memory contents is read by the instruction Get Data.
  • Page 42 CR. GETP\r Get Parameter After sending this instruction the entire set of parameters of the VC120 is transmitted to the PC. The parameter set has the following format: \r Magnitude F=f (Hz)

  • Page 43: First Connection With The Pc

    A simple way to check the function of instructions is to use a terminal program like “Termite” by CompuPhase. Connect the VC120 to an available USB Port of your PC and switch on the VC120. Start the terminal program and create a new connection for the used virtual COM- Port.

  • Page 44: Power Supply

    VC120 is supplied by the internal accumulator. In this case the accumulator must be sufficiently charged. If the VC120 cannot be switched on without mains supply the reason may be a dis- charged accumulator. The charge condition is indicated by an. It can show the following conditions: LED permanently green: The instrument is powered by the accumulator.
  • Page 45 When the mains adapter is unplugged during operation the VC120 switches off without saving setup and measured data. Charging the accumulator starts as soon as the mains adapter is connected. The ac- cumulator is monitored to prevent overcharging. Two charge modes are available: Rapid charging charges the accumulator with the highest possible current.

  • Page 46: Transport And Maintenance

    VC120 back to the manufacturer. Metra will replace the accumulator pack and check the instrument. A change of the accumulator pack by...

  • Page 47: Technical Data

    9. Technical Data Exciter System Vibration acceleration (RMS) 1 m/s² Vibration frequency 70 .. 10,000 Hz Specimen weight maximum 400 g Basic accuracy at T = 23 °C ± 10°C f = (80, 160, 315, 630) Hz ± 70 Hz £ f < 1000 Hz 2 % typ.
  • Page 48 Signal Conditioner Input single ended, BNC socket Input voltage (pulse) = 500 V Input resistance in voltage and IEPE mode 100 M IEPE constant current source 3.8 .. 5.6 mA, Us > 22 V Gain ranges Charge 1/10/100/1000 mV/pC Voltage / IEPE 0/20/40/60 dB Sensitivity range of sensor to be calibrated 0.12 mV/ms ..
  • Page 50 Declaration of Conformity According to EMC Directive 2014/30/EC Product: Vibration Calibrating System Type: VC120 (from Ser. no. 160000) It is hereby certified that the above mentioned product complies with the demands pursuant to the following standards: DIN EN 61326-1: 2013...

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