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MMF VM30-H Instruction Manual

Human vibration meter
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Instruction Manual
Human
Vibration
Meter
VM30-H
02.02.xxx.xxx*
From Version
*How to find the version of your instrument: page 47
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 Human Vibration Meter VM30-H 02.02.xxx.xxx* From Version *How to find the version of your instrument: page 47 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...
  • Page 2 The latest edition of this document can be found under: http://www.mmf.de/product_literature.htm © Manfred Weber Metra Meß- und Frequenztechnik in Radebeul e.K. May/ 12 #193...

  • Page 3: Table Of Contents

    3. Menus............................2 Fundamentals of Human Vibration Measurement ..............4 4.1. Introduction........................4 4.2. EU Directive 2002/44/EC....................4 Human Vibration Measurement with the VM30-H..............7 5.1. Switching On and Connecting the Sensor .................7 5.2. Hand-Arm Vibration Measurement with the VM30-H............8 5.2.1. Measuring Points for Hand-Arm Vibration ..............8...
  • Page 4 Viewing Saved Measurements on the Display...............30 Data Transmission to the PC....................31 13.1. Preparing the Import of Data into Excel................31 13.2. Importing VM30-H Data with the Excel Macro ............31 13.3. Calculation of the Daily Exposure Value A(8)..............33 13.4. Function of the Excel Macro ..................36 13.5.
  • Page 5 Technical Data........................50 Appendix: Warranty Declaration of Conformity...

  • Page 6: Purpose

    1. Purpose Thank you for choosing a vibration meter from Metra! The VM30-H was developed for the measurement of human vibrations. In addition, it is suited for many other fields of vibration measurement such as machine vibration, building vibration or quality control.

  • Page 7: Menus

    Battery compartment Reset Figure 3: Battery compartment and reset button 3. Menus Main Menu MENU 1/8: Gain Gain Range X Gain Range Y Gain Range Z M anually by SAVE key with / without comment with / without time with / without date 2/8: Recording setup by data logger Select time unit...
  • Page 8 Signal Setup Menu RANGE Human Vibration Selection of the Acceleration vibration quantity Velocity Displacement Band filters and Filter weighting filters for selected vibration quantity Running RMS (1 s) MTVV Max. running RMS A(T) Interval RMS eVDV Estimated vibr. dose Total vibration value PEAK Peak value (1 s) PEAK...

  • Page 9: Fundamentals Of Human Vibration Measurement

    4. Fundamentals of Human Vibration Measurement 4.1. Introduction Vibrations acting on the human body are called human vibration. The main purpose measuring human vibration is the prevention of health risks and the evaluation of comfort, for example in vehicles. Two categories are distinguished: •...
  • Page 10 Hand-Arm Vibration Whole-Body Vibration Exposure Action Value 2.5 m/s² 0.5 m/s² Exposure Limit 5 m/s² 1.15 m/s² Once the exposure action value is exceeded, the employer shall establish and implement a program of technical and and organizational measures intended to reduce to a minimum exposure to mechanical vibration, taking into account in particular: •...
  • Page 11 Daily exposure may consist of several activities with different vibration magnitudes. This can be the case if there are longer interruptions in the work process, if the work equipment or its way of use is changed. Resulting daily exposure is calculated: ...

  • Page 12: Human Vibration Measurement With The Vm30-H

    5.1. Switching On and Connecting the Sensor Switch on the VM30-H by pressing the ON/OFF key for at least two seconds (compare p. 16). Plug in the sensor cable or unplug it shortly to activate the sensor detection. Select the connected sensor (hand-arm or whole-body) using the ▲▼...

  • Page 13: Hand-Arm Vibration Measurement With The Vm30-H

    5.2. Hand-Arm Vibration Measurement with the VM30-H This section will give you basic instructions for the measurement and evaluation of hand-arm vibrations based on the standard ISO 5349 and the guideline VDI 2057, Part 2. Please consult the original documents for detailed explanations.

  • Page 14: Settings On The Vm30-H

    Figure 6: Coordinate system of the hand (from ISO 5349-1) 5.2.2. Settings on the VM30-H For hand-arm vibrations it is recommended to report both the interval RMS for each axis and vibration total value (Ahv). Therefore both measurements are described in this section.

  • Page 15: Reporting Of Measuring Results

    A description can be found on page 31. Notice: You may simplify the setup of the VM30-H by using pre-defined setups. Press the ▼ (LOAD) key to choose from 10 stored setups. In the original configuration setup no. 0 contains the settings for the interval RMS of hand-arm vibration and setup no.

  • Page 16: Whole-Body Vibration Measurement With The Vm30-H

    - Daily exposure A(8) - Assessment of measurement uncertainty 5.3. Whole-Body Vibration Measurement with the VM30-H This section will give you basic instructions for the measurement and evaluation of whole-body vibrations based on the standard ISO 2631 and the guideline VDI 2057, Part 1. Please consult the original documents for detailed explanations.

  • Page 17: Settings At The Vm30-H

    23). Figure 7: Coordinate systems for whole-body vibration to ISO 2631 5.3.2. Settings at the VM30-H For whole-body vibration interval RMS is measured for each coordinate direction. Select first the measuring ranges for X, Y and Z. A good method is starting with the most sensitive range.
  • Page 18 0,01 1000 Figure 8: Frequency weightings for whole-body vibration The weighting filter to be used depends on the point where the vibrations enter the human body and on the coordinate direction (Table 1). A difference is also made between the evaluation of health risks and comfort.

  • Page 19: Evaluation Of Health Risks

    If the vibration exposure is divided into different sections, measurements have to be performed for each section. Notice: You may simplify the setup of the VM30-H by means of pre-defined setups. Press the ▼ (LOAD) key to choose from 10 stored setups. In the original configuration setup no. 2...

  • Page 20: Comfort Evaluation

    5.3.4. Comfort Evaluation The subjective perception of vibrations is determined by a perception limit and a pain threshold. Table 2 gives a rough orientation for the relationship between vibration level and perception. However, perception strongly varies with the test person and depends, in addition, on other influences like age, gender, health condition, attentiveness, type of activity, temperature and noise.

  • Page 21: Switching The Instrument On And Off

    6. Switching the Instrument On and Off To switch on the VM30-H, push the ON/OFF key and hold it for 2 seconds. The instrument displays its software version and starts to display measuring values based on the last settings.

  • Page 22: Display

    8. Display The VM30-H has a graphical LCD with a resolution of 32 x 120 dots. It displays clearly the measuring values of three channels simultaneously including units and additional information. Pressing the LIGHT key switches on the backlight. By repeated key press the light is switched off again.

  • Page 23: Signal Setup

    Vibration displacement, double integrated acceleration signal 9.2. Filters The filter menu appears after a vibration quantity has been selected. The VM30-H provides a set of band-pass or weighting filters for each vibration quantity mode. The weighting filters for human vibration conform to ISO 8041 and cover most applications in this field.

  • Page 24: Weighting Filter Wc

    9.2.1.2. Weighting Filter W The weighting filter W is intended for the measurement of whole-body vibration at the seat back in the direction perpendicular to the spinal column to ISO 2631-1. 10,00 1,00 0,10 0,01 1000 Figure 12: Weighting filter W 9.2.1.3.

  • Page 25: Weighting Filter We

    9.2.1.4. Weighting Filter W The weighting filter W is used for the measurement of rotational whole-body vibration in three axes to ISO 2631-1. 1,00 0,10 0,01 1000 Figure 14: Weighting filter W 9.2.1.5. Weighting Filter W The weighting filter W is used for the evaluation of whole-body vibration in the direction along the spinal column with regard to hand control and visibility to the standard BS 6841.

  • Page 26: Weighting Filter Wh

    9.2.1.6. Weighting Filter W The weighting filter W is intended for measuring hand-arm vibration in three axes to ISO 5349- 10,00 1,00 0,10 0,01 1000 10000 Figure 16: Weighting filter W 9.2.1.7. Weighting Filter W The weighting filter W is used for measuring vibrations acting on the head of a recumbent person in vertical direction (perpendicular to the lying surface) to ISO 2631-1.

  • Page 27: Weighting Filter Wk

    9.2.1.8. Weighting Filter W The weighting filter W is used for measuring whole-body vibrations in the direction of the spinal column in seated and standing position, for measurements in vertical direction (perpendicular to the lying surface) in recumbent position and for vibrations in all three directions acting on the feet in seated position to ISO 2631-1.

  • Page 28: Combined Weighting Filters

    Z axis shall always point into the direction of the spinal column. However, the Z axis measured by the VM30-H will point vertically to the back in the mentioned cases. To compensate this, the displayed X and Z values must be swapped.

  • Page 29: Display Modes

    (integration variable) τ is the integration time (1 second for VM30-H) is the time of observation If an overload occurs during the measurement of running RMS, a message OVER LOAD is displayed instead of the corresponding measuring value until normal magnitudes are measured again.

  • Page 30: Estimated Vibration Dose Value (Evdv)

    Its particular advantage is the higher sensitivity to vibration peaks. The VM30-H uses instead of VDV the so-called Estimated Vibration Dose Value with the display abbreviation “eVDV”. It is described in annex B.3.1 of ISO 2631-1 as: ⋅...

  • Page 31: Vibration Total Value (Ahv)

    ISO 2631-1. When measuring the Vibration Total Value, the VM30-H automatically sets the measuring ranges of all three channels to the highest one of the three selected ranges. If autoranging has been activated, a message is displayed after the selection of Ahv, showing that autoranging is not available in this mode and the gain of all channels is set to 0.1,...

  • Page 32: Maximum Peak Value (Peak↑)

    9.3.7. Maximum Peak Value (PEAK↑) Maximum peak value with the display abbreviation “PEAK↑”is the highest absolute magnitude (negative or positive) of the instantaneous vibration signal (human vibration, acceleration, velocity or displacement) since the start of measurement. A new measurement is started by the ESC key which resets the peak memory.

  • Page 33: Loading User-Defined Setups

    ▲▼ keys. After pressing OK the VM30-H will measure with the new settings. 10. Measuring Range and Autoranging The VM30-H has four measuring ranges which can be selected in menu “1/8: Gain”. Choose one after the other the measuring ranges for X, Y and Z. The ranges displayed in the menu depend on the selected vibration quantity.

  • Page 34: Overload Indication

    (manually by SAVE key) or time-controlled recording (by data logger). The two recording modes cannot be mixed in the memory. The VM30-H can either hold manually recorded or logger data. If the instrument should detect data of the other type in its memory, a warning will inform you that the memory will be overwritten.

  • Page 35: Automatic Recording In The Data Logger Mode

    “2/8: Recording setup” if desired. It is useful to lock the keys of the VM30-H when it is in the log mode to avoid interruption by accidental key pressure. Press the LOCK key and confirm by OK. Now all keys are disabled. To unlock, press the LOCK key again and confirm by OK.

  • Page 36: Data Transmission To The Pc

    Microsoft Excel is a widely used software for calculation and visualization of data in table form. It also enables data to be converted into other formats. Therefore the data transmission from the VM30-H to the PC is based on Excel. 13.1. Preparing the Import of Data into Excel The instrument uses a serial (RS-232) interface for PC connection (see section 17).
  • Page 37 19200 baud. Higher baud rates are possible depending on the PC speed. At the VM30-H the baud rate is selected as follows: Press the MENU key. Select by the ▲▼ keys “8/8: Device settings”. Go to submenu “5/6: Baud rate“ and choose the desired baud rate by ▲▼.

  • Page 38: Calculation Of The Daily Exposure Value A(8)

    If data transmission has failed, please check if you have selected the correct serial interface number (Figure 21) and if the baud rates of the Excel macro and the VM30-H match. After checking these settings you can repeat data transmission. The stored data remains in the VM30- H memory until it is erased by the user (MENU, „4/8: Erase memory“).
  • Page 39 The Excel macro of the VM30-H allows the calculation of A(8) for several activities and persons. Precondition for A(8) calculation is saving several vibration total values (Ahv) by means of the manual recording mode (compare page 29). For each activity of each person a measuring value including an informative comment is saved.

  • Page 41: Function Of The Excel Macro

    Feel free to modify the macro or the Excel file according to your requirements. SENDSTRING (String) transmits a character string Data is transferred only in the direction from the VM30-H to the PC after the PC has transmitted the start character “#” by the SENDSTRING command.

  • Page 42: Transmission To Pc By A Terminal Program

    13.5. Transmission to PC by a Terminal Program The VM30-H transmits the stored data as formatted text. Therefore it is also possible to use a terminal program for the display of measured data. The following example explains how to use the program Termit which is available for downloading from: http://www.compuphase.com/software_termite.htm...

  • Page 43: Time And Date

    Figure 26: Downloaded VM30-H data in the terminal 14. Time and Date The VM30-H has a real-time clock providing time and date for data recording. It can be changed in the menu “5/8: Time and Date”. Successively enter hours, minutes, seconds, year, month and day using the ▲▼...

  • Page 44: Calibration And Function Check

    Press OK and choose the calibration mode “By vibration calibrator”. The calibration feature of the VM30-H is based on a reference vibration signal of 10 m/s² (RMS) with a frequency of 159.2 Hz. Several calibrators of this type are available, for example VC2x series of Metra.

  • Page 45: Mechanical Calibration

    Calibration is performed at a reference signal of 5 m/s² (RMS) / 80 Hz for hand-arm sensors and at 0.5 m/s² / 16 Hz for whole-body sensors. At the VM30-H the filter 0.4 Hz – 100 Hz or 10 –...
  • Page 46 Generator signal Typical display values (m/s²) Chann. Settings at VM30-H Max. error Level (RMS) Frequency Filters at reference frequency: 5 mV 79.58 Hz Wh, HV, A(T), G=1000 0.101 0.101 0.101 5 mV 15.92 Hz Wb, HV, A(T), G=1000 0.4063 0.4063 0.4063...
  • Page 47 500 mV 4 Hz Wm, HV, RMS, G=10 40,9 40,9 40,9 11 % 500 mV 8 Hz Wb, HV, RMS, G=10 51,3 51,3 51,3 21 % 500 mV 8 Hz Wd+Wc, HV, RMS, G=10 12,8 12,8 44,7 11 % 500 mV 8 Hz Wd+Wk, HV, RMS, G=10 12,8...

  • Page 48: Function Check

    Hz and RMS display. Adjust 1250 the vibration calibrator to 159.2 Hz and 10 m/s². The VM30-H shall display a value between 9.5 and 10.5 m/s² in the respective direction. The displayed vibration in the other directions caused by transverse excitation is not relevant.

  • Page 49: Automatic Shut-Off Timer

    A protective cover makes the socket waterproof (IP65) when not in use. For connection with the Sub-D9 socket of a PC serial interface the interface cable VM30-H is supplied with the instrument. For PCs without serial interface a commercially available serial- to-USB converter can be used which simulates a serial interface on the PC.

  • Page 50: Power Supply

    19. Power Supply 19.1. Battery Operation The VM30-H is powered from three Mignon / LR6 / AA type cells. It was designed particularly with regard to a long battery life time. Both Alkaline cells and NiMH accumulators can be used. A battery indicator with 20 segments is displayed in the upper right display corner.

  • Page 51: External Supply

    Do not throw batteries into domestic waste. 19.2. External Supply The VM30-H can be supplied externally via a socket type Binder 711 (5 pins, female). The supply voltage range is 8 to 12 VDC with a current consumption below 200 mA. The voltage source must be able to supply a peak current of 1 A in the moment after switching on the VM30-H.

  • Page 52: Hardware And Firmware Versions

    After this, download the firmware file vm30-h.hex from our web site and save it in your working directory. Connect your VM30-H via a serial interface cable to your PC. If your PC has no serial interface, you may use the supplied USB/RS-232 converter. Please verify that this converter is recognized as COM port in the device manager of your PC.
  • Page 53 Click the “Send” button in the firmware updater utility. The update takes two to three minutes. Progress is indicated at the VM30-H by the display back light flashing.  The update process must not be interrupted! Reception errors are signaled by a PC error message. If an error has occurred, restart the firmware update utility.

  • Page 54: Questions And Answers

    You have attempted to import more than 5 log files enough worksheets." when I import from the VM30-H. First make sure that you wanted to data from the VM30-H. How can I record log files but not single measurements in the avoid this? manual mode.
  • Page 55 25. Technical Data Measuring ranges with sensor 1mV/ms Human vibration: 0.10-12.00 / 1.0-120.0 / 10-1200 / 100-6000 m/s² peak Acceleration: 0.10-12.00 / 1.0-120.0 / 10-1200 / 100-6000 m/s² peak Velocity: 0.001-0.120 / 0.010-1.200 / 0.10-12.00 / 1.00-60.00 m/s peak Displacement: 0.001-0.120 / 0.010-1.200 / 0.10-12.00 / 1.00-60.00 mm peak with sensor 10mV/ms...
  • Page 56 Overload indication: Separately for each channel, at inputs and after integrators. Thresholds for measuring ranges: ±1.2 mV / ±12 mV / ±120 mV / ±6 V Memory: Flash memory for 1000 to 3000 measuring values, depending on the recording mode, optionally with time, date and comment Recording modes: Manually by SAVE key or...
  • Page 57 Limited Warranty Metra warrants for a period of 24 months that its products will be free from defects in material or workmanship and shall conform to the specifications current at the time of shipment. The warranty period starts with the date of invoice. The customer must provide the dated bill of sale as evidence.
  • Page 58 Declaration of Conformity Product: Human Vibration Meter Model: VM30-H It is hereby certified that the above mentioned product complies with the demands pursuant to the following standards: EN 55022: 1998 EN 55024: 1998 Responsible for this declaration is the producer Manfred Weber Metra Mess- und Frequenztechnik in Radebeul e.K.

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