The Ultimate Vibration Meter Buyers Guide

Introduction

Vibration meters come in a wide variety of flavours covering numerous applications, standards and regulatory requirements. Choosing the wrong instrument for the task at hand can render your measurements useless, so it is far better to narrow down your choice first.

This guide will run through the many applications and highlight the differences in equipment features and specification required for each task.

Applications

Some vibration measurement tasks require very specific features not found on all instruments, so selecting the application you are involved in is of utmost importance. The applications commonly encountered are as follows.

• Hand-Arm (HAVS) and Whole-Body Vibration (WBV) for compliance with the Control of Vibration at Work Regulations 2005
• Nuisance and disturbance (Comfort) of humans in buildings or on transportation
• Building damage assessment
• Assessment for equipment. Sensitive to vibration
• Blasting in quarries and mines
• Machinery condition monitoring
• Vibration diagnostics

Hand-Arm and Whole-Body Vibration

The Control of Vibration at Work Regulations 2005 requires some specific features that are only found on instrumentation designed for the task. The following features will be needed to complete a risk assessment.

Hand Arm Vibration

• Acceleration: Human Vibration measurements use Acceleration as a fundamental parameter, which is normally measured using an accelerometer.
• Tri-Axial measurement: To quantify any vibration completely requires measurement in the three dimensions of space. These are often referred to as X, Y and Z. You vibration meter should ideally be able to combine these to create a resultant overall vibration figure.
• Frequency filter W_h: This is defined in ISO 5349-1:2001 and ensures that measurements match the sensitivity of the human hand to vibration, which is generally very low, at between around 5 and 20Hz.
• A_eq: which is the Equivalent Energy Average of the Acceleration value and is based on the rms of a signal. This essentially means the average vibration level measured in a specific way. Not all vibration meters carry this parameter.
• A(8): This is optional as it is a post measurement calculation of the exposure related to the amount of time a worker is exposed to the A_eq as measured.

So long as the vibration meter you wish to use has the frequency weighted Acceleration average (A_eq), then you will be able to use it for hand arm vibration assessments to the Control of Vibration at Work Regulations 2005.

There are two products that fit this application perfectly, which are the Vexo and the Vib A(8). Both can be found here. https://www.castleshop.co.uk/technical-safety/vibration-meters/hand-arm-vibration-meters

Vexo Hand Arm Vibration Meter

The Vexo vibration meter is available in two versions, both of which are dedicated hand arm vibration measurement meters with no other features, meaning they are ultimately simple to use and require no set-up or a detailed understanding of instrumentation.

• Dedicated to hand arm vibration
• Incredibly simple to use
• Exposure and points calculated
• Rugged, pocket size meter

The Vexo is available in 2 versions

• Standard – with dedicated fixed accelerometer. https://www.castleshop.co.uk/castle-ga2006h-vexo-hand-arm-vibration-meter.html
• Plus – miniaturised accelerometer with replaceable cable. https://www.castleshop.co.uk/hand-arm-vibration-meter-castle-vexo-h-plus.html

Vib-A(8) Vibration Meter

Offering a larger memory, large display, extra monitoring features and most importantly, the ability to add whole-body vibration measurement, the Vib-A(8) is a step up from the Vexo for more demanding applications.

• Larger memory
• Bigger display
• Better measurement range
• Time-history data logging
• More calculated parameters
• Ability to add whole body vibration sensor

The Vib-A(8) is available as a system. https://www.castleshop.co.uk/viba-8-hand-arm-vibration-system.html

For whole-body assessments, you will require a few different features:

Whole-Body Vibration (WBV)

• Seat Pad Accelerometer: this is found in ISO 8041-1:2017 and is a large rubber disk on which the subject sits or stands to assess the vibration passing into the body.
• Frequency Filters W_d and W_k: These are described in ISO 2631-1:1997 and are used for WBV assessments. More specifically, W_d is used for the X and Y axes, which would be through the chest and across the shoulders of a seated person respectively. W_k is only appropriate for measurement along the length of the spine, normally denoted as the Z axis.
• Dominant Axis: Unlike hand arm vibration, WBV assessments are carried out using the single biggest measurement from the three axes after a correction multiple of 1.4 is applied to the X and Y axes. It is most helpful if you vibration does this for you!
• Vibration Dose Value (VDV): This is optional and is normally used by consultants who wish to study the effects of vibration shocks and jolts in more detail. VDV accounts more for vibration with higher levels of shocks.

Vib-A(8) Vibration Meter

The Vib-A(8) can be bought as a hand arm only kit, whole-body only or both. You can also add the other sensor at any point, whichever one you buy first..

• Incredibly simple to use
• Corrected dominant axis results
• W_d and W_k filters
• Axis mapping for horizontal measurements
• VDV measurement
• Exposure and points calculations

The Vib-A(8) is available as a whole body only kit here. It is also possible to add the hand arm vibration sensor.

https://www.castleshop.co.uk/viba-8-hand-arm-and-whole-body-vibration-meter-4678.html

Nuisance and Disturbance (Comfort)

Assessing nuisance or the comfort of people in buildings or on various modes of transport is the subject of ISO 2631 in its various parts. This uses the seat pad measurement sensor with different filters depending on the application in question.

Be sure that the vibration meter you are buying supports the filters you require for your particular task.

It is also important that the vibration meter can measure Vibration Dose Value (VDV), which is specially designed to account for shock vibrations as these are considered more disturbing and annoying that steady vibrations.

Svantek SV106 Human Vibration Meter

The 106 from Svantek has some of the above filters in-built, including W_d, W_k, W_m, W_b and W_h. It is also capable of measuring from 2 sensors at once, making it possible to measure the source as well as the body-transmitted vibration levels.

• Tri-Axial vibration system and analyser with optional whole-body vibration
• Measures vibration levels meeting ISO 8041:2005, ISO 2631-1,2 & 5 (including VDV and MTVV) and ISO 5349
• Dual input with 2 profiles with each channel
• Micro SD card for mass data storage
• Easy to use interface with colour display

Building Damage Assessment

Construction works near residential properties can cause concern for residents with regard to the integrity of their property. High enough levels of vibration can cause cracks in plaster and sometimes even structural damage. Piling works and demolition activities can produce particularly high levels.

• Peak Particle Velocity (PPV): This is the single biggest velocity reading from a moving surface.
• Displacement: This is optional and is the distance moved by a vibrating surface, usually measured in micro metres µm
• Frequency filters: These will usually be cut-off filters to allow measurements up to or above a given frequency.

Damage criteria are set using Peak Particle Velocity (PPV), which is a completely different kind of measurement that those used for human vibration assessments. Fundamentally, velocity measurements are measured using a geophone as opposed to an accelerometer. This is essentially a loudspeaker in reverse, where the vibration causes a magnet to move in a coil, which produces a voltage that can be measured. In many modern vibration meters, it is possible to calculate the PPV using an accelerometer and vice versa, using a geophone to derive acceleration.

Filters work differently on building vibration meters too, with cut-off filters generally used instead of filter curves. For example, in BS 5228-2:2009 the criteria are split for those between 4Hz and 15Hz and then anything above 15Hz. Clearly a vibration meter used for assessments to this standard need to be able to filter accordingly.

A range of ground borne vibration meters capable of PPV measurement can be found here. https://www.castleshop.co.uk/environmental-testing/ground-and-building-environmental-vibration

Svantek SV803 Wireless Vibration Meter

The SV803 uses in-built geophones to measure down to incredibly low vibration levels. It also has the capability of calculating VDV values if required. Being wireless, this instrument connects to the internet where all settings and data are managed.

• BS 7385-1 (ISO 4866), DIN 45669-1, DIN 4150-3 and BS 7385-2 standards compliant.
• Dominant Frequency using FFT method
• SMS and email alerts
• Works with noise and dust and weather monitors

The SV803 can be found here. https://www.castleshop.co.uk/sv803-wireless-vibration-monitor.html

Vibration Sensitive Equipment.

Installing sensitive machinery and equipment into buildings can often require strict adherence to maximum permitted vibration levels. This is true for equipment such as high magnification microscopes, photolithography for circuit board manufacture and some laser-based equipment.

Assessments for vibration sensitive equipment are carried out using Vibration Criteria curves, originally defined in IEST-RP-CC024.1 from the Institute of Environmental Science and Technology in the USA but since extended. These criteria require velocity measurements in 1/3 octave bands, which are then compared against the criteria to determine the compliance level VC-A to VC-M (VC-M being the lowest levels of vibration therefore the most sensitive equipment)

• Velocity measurement
• 1/3 Octave Bands
• Ideally in-built Vibration Criteria
• Very low measuring range

Vibration Criteria (VC) Curves

Achieving criteria of VC-K and above requires especially low measurement values and therefore specialised measuring equipment. The Svantek SV803 is capable of achieving these levels,

https://www.castleshop.co.uk/sv803-wireless-vibration-monitor.html

Blasting in Quarries and Mines

This is another highly specialised application, requiring the right kind of vibration meter with very specific features. These include.

• Peak particle Velocity (PPV)
• Dominant Frequency (Hz)
• Air (Blast) Over Pressure (AOP)

Blast monitoring is usually carried out using a geophone to capture the PPV and the dominant frequency, which is calculated in the instrument. Air Over Pressure is measured using a sound meter measurement microphone and uses a very low frequency filter to capture the blast wave pressure change, which can then be correlated with the vibration signal.

A range of ground vibration meters can be found here. https://www.castleshop.co.uk/environmental-testing/ground-and-building-environmental-vibration

A good example of a meter containing all the required features is the Surewave CM3

SureWave CM3

This instrument is capable of measuring vibration and/or noise and can be used for many applications within ground borne vibration assessments. It is particularly suited to blast measurements from explosives.

• User-friendly PC software for data analysis to BS6472, BS4142, DIN 4150 and USHM/OSMRE standards
• Graphics display to view previous results
• Modem option with SMS text alerts
• Remote operation and data collection
• Alarm option with audio/visual warning
• Unlimited cable lengths and extended battery life via external battery socket [multiple blast event storage in memory]
• 3 event timer providing automatic unattended monitoring
• Noise Statistics

Machinery Condition Monitoring

Condition Monitoring is the measurement, recording and analysis of machinery parameters which can determine the machinery’s health. The current machine condition or signature, is compared with earlier condition or fingerprint, often taken when a machine was new. It can then be used as an indicator when detecting potential failure before it occurs.

Vibration is one of the key measures used to assess the condition of machinery, especially with rotating parts. To be able to use a vibration meter for basic condition monitoring, you will need the following features.

• Velocity measurement
• Data recording, ideally with a location identifier
• Ability to monitor trends (this can be done manually)
• Low-pass machinery filter
• Hi-pass bearing filter

A range of vibration condition monitoring equipment can be found here. https://www.castleshop.co.uk/inspection-test/condition-monitoring/vibration-condition-monitoring

Castle Vexo S Vibration Meter

The Vexo is a dedicated condition monitoring instrument that has all the required features for machinery and bearing condition trending.

• Machinery condition to ISO 10816-1, 3 & 7
• Bearing condition indication
• Trending analysis (with optional VibdataPro)
• Single Axis mode for simple setup
• Large colour display
• Large ‘Flash’ memory
• Re-chargeable battery pack and charger
• Only 3 operational buttons for simple use
• Built tough with rugged accelerometer and cable

Dedicated to monitoring vibration levels accurately and precisely in industrial machinery such as bearing housings, rotating machinery or any other source of mechanical vibration, the Vexo S is perfectly suited to monitoring machine conditions and faults.

Designed to be simple to use and easy to operate, the Vexo S has 3 operational buttons with virtually no set-up meaning you can simply turn it on press Record and start measuring. With a large colour display, it’s also easy to take instant readings.

The Vexo S can be found here.

https://www.castleshop.co.uk/ga2006s-vexo-single-axis-vibration-meter.html

TPI 9070 Smart Vibration Analyser

This is the 9070 Smart Vibration Analyser which is a simple, easy to use, low-cost vibration meter which records, analyses and displays vibration signals at the push of a button. The vibration values are displayed with colour coded alarm levels for ISO values and bearing damage (BDU). It identifies complex issues using the 800-line spectrum with zoom and cursor.

• ISO Built-in Alarms
• Easily identify bearing problems with BDU Reading
• 800-line FFT (spectrum)
• Ruggedized IP67 case
• 3-year Limited Warranty
• Full Colour OLED Display
• Built-in accelerometer with stinger
• Optional long stinger and magnetic mount available
• 1x unbalance
• 2x misalignment
• 3x looseness

The TPI 9070 can be found here. https://www.castleshop.co.uk/tpi-9070-smart-vibration-analyser.html

Vibration Diagnostics

Once you have determined that there is a problem with some machinery, or if you are developing a product that is not performing then using some more advanced vibration analysis techniques can help to narrow down the issue you are facing. Equipment like this is also used for investigating when thing go horribly wrong!

• Fault identification
• Product development
• Equipment failure investigation

The equipment for diagnostic vibration analysis comes with a variety of different features and most of this equipment can be used to carry out vibration measurements for a variety of other applications. The key feature required for analysis if Fast Fourier Transform (FFT), which is a method used to determine the frequency spectrum of a vibration signal.

• Fast Fourier Transform (FFT)
• Acceleration, Velocity and Displacement modes
• ‘Windowing’ to capture all of the vibration signal
• Analysis techniques such as 3D visualisation or waterfall displays
• In-built analysis models to provide instant outputs.

A range of FFT vibration meters can be found here. https://www.castleshop.co.uk/inspection-test/condition-monitoring/vibration-condition-monitoring

TPI 9071 Smart Vibration Meter

This powerful little vibration meter will carry out ISO machine alarms and BDU reading to indicate overall machine and bearing condition. It provides a clear picture of 1X (unbalance), 2X (misalignment) and 3X (looseness) machine problems. There is an 800-line spectrum with zoom and cursor to identify complex issues. The meter will collect and store test data with a storage space of 200 readings.

• Full Colour LED Display
• Standard Cable mounted accelerometer with magnet
• ISO Built-In Alarms
• Easily Identify Bearing Problems with BDU Reading
• Easily Identify Machine Faults with Built-In Band Filters: 1X (unbalance), 2X (misalignment), 3X (looseness)
• 800 Line FFT (Spectrum)
• Ruggedized IP67 Case
• Built-In ISO Alarms
• Find Machine Faults before they stop your machine
• Increase Productivity and Lower Maintenance Costs

The TPI 9071 can be found here. https://www.castleshop.co.uk/tpi-9071-smart-vibration-meter.html

Conclusion

Vibration measurement applications vary widely, and it is vital to select the correct equipment for the task at hand. If you end up with an instrument that has critical featured missing, then you will be unable to complete your assessments.

It is important to understand the application at hand and so making sure you have had the correct training is a good place to start. It is also important to seek advice from a reputable manufacturer or equipment supplier to ensure that you are purchasing or hiring the best equipment for your current needs.