CASTLE GA2002 User manual

www.castlegroup.co.uk
Operating Manual
Pocket Vibration Meter Range
GA2002
&
GA2003

Thank you for buying a Castle product, I am sure you will find both the goods and
the service to be of the highest quality but if not, then please feel free to write to
me personally and I will ensure that your needs are dealt with immediately.
This manual is designed to show you the operation of the goods you have
purchased and a very brief insight into acoustics itself. If you would like to
become a competent person in the eyes of the law, then you may like to know
more about our Competent Persons training course for Noise at Work
Reulations. You can visit www.castle-training.com to find out more.
It is my intention for Castle Group Ltd to provide a wide range of technical health
and safety products and Services of the highest standard. If you would like to
know more about any of our other products and services then please telephone
on [phone] or visit www.castlegroup.co.uk
Simon Bull
Managing Director

Copyright
This manual is copyrighted with all rights reserved. Copying in part or in whole is
prohibited without the prior written consent of Castle Group Ltd.
Precautions
Only operate the instrument as described in this manual.
These are precision instruments, protect from shocks and vibrations.
Ambient conditions for the operation of the unit are as follows:-
Temperature: -10C to +50C
Relative Humidity: 25 to 90%
Protect the unit from extremes of temperature and humidity, direct sunlight
and air with a high salt or sulphur content.
Always turn the unit off after use. Remove the batteries from the instrument
when not in use.
Do not use any solvents or cleaning agents on the instrument. Use only a
soft dry cloth or a soft cloth lightly moistened with water when necessary.
Do not allow any conductive objects, such as wire or metal particles to enter
the unit.
Do not try to disassemble the instrument or attempt any repairs as this will
invalidate your warranty. Take a note of the condition of the instrument and
contact your authorised Castle service station.
To ensure continued precision performance of your instrument have it
checked and serviced at regular intervals.
Contacting Castle Group
This manual contains complete operating instructions for the Castle Pocket
Vibration Meter range, read it carefully and you will quickly become familiar with
your instrument and its operation.
If you do encounter problems with the operation of your instrument please feel
free to contact customer support with your enquiry on: -
Telephone:
[phone]
Fax:
[phone]
Website:
www.castlegroup.co.uk
Email:
[e-mail]
[e-mail]

Contents
Introduction............................................................................................... 1
Using the Manual.................................................................................... 1
Notes Before Use ................................................................................... 1
Measuring Vibration.............................................................................. 2
Hand ARM (HARM) Vibration Direction .............................................................. 4
Transducer Mounting................................................................................................... 4
Vibration Level.................................................................................................................. 5
Frequency Weighting.................................................................................................... 5
Battery Installation / Check............................................................... 7
Fitting the Accelerometer ................................................................... 7
Switching the Instrument On & Off.................................................. 8
(Status) Button........................................................................................ 8
(Parameter) Buttons............................................................................. 9
Changing or Viewing Instrument Settings ................................. 10
Setup Screen.................................................................................................................10
Detector .......................................................................................................................10
Parameter...................................................................................................................11
Filter ...............................................................................................................................12
Range ............................................................................................................................12
Viewing the Setup Screen .......................................................................................12
Changing Settings within the Setup Screen ...................................................12
Storing Data .......................................................................................... 13
Reviewing/Clearing Stored Data................................................... 13
Viewing Data ..................................................................................................................13
Clearing Data.................................................................................................................14
Calibration .............................................................................................. 14
Warranty and After Sales Service................................................ 15
EC Declaration of Conformity.......................................................... 16
Technical Specifications.................................................................... 17
Accessories............................................................................................ 18
Instrument Disposal ........................................................................... 18
Instrument Details .............................................................................. 19
Disclaimer............................................................................................... 19

Page 1
Introduction
Thank you for purchasing your product from Castle Group Ltd.
The Castle Pocket Vibration Meter range has been designed to deliver cost
effective vibration measurement solutions.
Your instrument can cater for various degrees of experience with it being
simple to to operate and interprate the measurement results.
Using the Manual
In the course of this manual a named button written in BOLD means press
that button E.g. OK means press the OK button
Notes Before Use
Due to the compact screen it has not been possible to fit the full notation for
velocity units and the value, so the units displayed as ms-1 are actually
millimeters per second or mms-1.
There is a slight delay between switching the unit off and it turning off, this is
while your data is backed up. If the power switch is pressed during this delay
your settings may be lost.
Holding your finger on a key will mean the key is pressed successively as far
as the instrument is concerned. To avoid confusion when using the keypad,
press the keys firmly and release them quickly.
If using the instrument with a magnet make sure you have removed the
keeper (metal disc covering the magnet) from the magnet before use.

Page 2
Measuring Vibration
It is advisable to validate your instrument prior to, and after taking
measurements using a known vibration source such as the Castle GA606
Vibration Calibrator.
To ensure measurements are as accurate and as repeatable as possible
always ensure that your cable is tightened securely to your accelerometer
and that the accelerometer is mounted as securely and as flush as possible
to the vibration source. The trailing cable of the accelerometer should also
be attached to the vibration source without creating a potential hazard for
the operator or other people. Where practicable it may be beneficial to
permanently attach the accelerometer cable.
Where possible always mount the accelerometer as near to the centre of
where the operator holds and grips the vibration source. In reality this is not
always possible and the best compromise must be achieved.
Measurement durations are not governed but as a rule of thumb use an
absolute minimum time period of 15 seconds for Hand Arm Vibration. It is
recommended depending on the process that a minimum period of 3 to 15
minutes is used for Hand Arm vibration. These increased durations will
undoubtedly increase the accuracy and repeatability of your measured
results.
The vibration is measured in one axis only and once all axes have been
individually recorded you will have to assess how long the operator is exposed
to the machine.
Taking the Vector sum acceleration is the preferred method of calculating
vibration dose although it is not the only option. It is possible to look at the
Dominant Axis. This means that once you have taken the X, Y and Z readings
you may take the largest one providing that it is larger than the other axes by
a factor of two or more.
The parameter A(8) is actually the partial vibration dose based on 8 hours. It
is calculated as follows: -
This parameter is given by the GA2003 providing the measurement period is
equal to the duration of the work.
Alternatively the AV (Linear Average Value) may be used in the above
equation (ah,w) and the time (t) is the daily exposure time for this operation
where i is the reference for the individual measurement and 8 is for the 8
hour day.
8
)8( ,
t
Aawh
i


Page 3
The result of this equation is the contribution to daily exposure and the
reason that this is used is to give a measurement to each of a number of
processes that may be carried out in one day. To calculate the overall daily
exposure from a set of partial exposures, the following equation is used: -
Where A1(8), A2(8) and A3(8) are the partial vibration exposure values for
each vibration source.
The nomogram shown below can also be used instead of the previous
calculation.
)8()8( 2
3
2
2
2
1)8()8(
AAA
A 

Page 4
Hand ARM (HARM) Vibration Direction
For Hand Arm vibration (GA2003 Only), the three axes being measured can
be measured in any orientation; however it is recommended that the
suggested axes indicated in the figure below are used. If this is not possible,
then choosing other axes orientation is permissible and will not affect your
measured data.
In all cases it is strongly recommended to make notes on the axes used
relative to the vibration source. This information will be required if vibration
control is to be implemented on the vibration source.
Transducer Mounting
If your Pocket Vibration meter is supplied with a spike probe this can be used
for the interface of the transducer to the vibration source.
Mounting of the single axis accelerometer to the vibration source can also be
achieved by tapping a stud into the vibration source and attaching the
accelerometer to the stud. Alternatively the stud may be adhered to the
device with an adhesive that dries rigid. Castle Group Ltd can supply a glue
and stud pack if required, (order code K01215).

Page 5
Vibration Level
For ease of use and where high levels of vibration may occur, the Pocket
Meter Vibration Range has been designed with 2 operating ranges.
Before you record measurements take the time to ensure you have selected
the optimum range for the process being recorded.
Generally the optimum range is generally the lowest range that can be
selected that does not produce an overload condition for the process being
monitored.
Where high levels of vibration are encountered the meter may register an
overload and in these circumstances the meter will display that this has
occurred. In such cases you will need to select a higher range to
accommodate the higher peak levels.
If the vibration levels are too low for the range selected then the meter will
display an under range condition. Under these circumstances you will need to
select a lower range.
Frequency Weighting
Vibration damage to the hand occurs when the hand absorbs the majority
of the vibration energy. If the vibration is slow, the wrist and arm joints will
damp the vibration energy. If the vibration is fast, the skin of the hand will
absorb the energy. In between, the hand itself absorbs vibration energy.
The HARM filter (GA2003 Only) selects the most harmful frequencies to a
human. The value given using the HARM filter displays not how much the
machine is vibrating but how much vibration is being absorbed by the hand.
The HARM frequency response is shown graphically below: -
-110
-90
-70
-50
-30
-10
0.01 0.1 1 10 100 1000 10000
Frequency (Hz)
Gain (dB)

Page 6
Both instrument types have a mechanical filter which has a flat pass band
useful for machine monitoring. The frequency response is shown below: -
-40.00
-35.00
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.00
5.00 0.1 1 10 100 1000 10000
Frequency (Hz)
Gain (dB)
The GA2002 model has a linear frequency weighting filter which does not
attenuate any vibration regardless of frequency. The frequency response is
shown below: -
-5.00
0.00
5.00 0.1 1 10 100 1000 10000
Frequency (Hz)
Gain (dB)