Introduction
How does the new instrument fit into the CEL range?
The new CEL350 & 350IS
dBadge models fit into the CEL-300 range
of personal noise dosimeters along with the existing CEL-320 and CEL-360
dosimeter models.
What models are there in the new range?
Currently there are two new models called the
CEL-350
dBadge Micro Noise Dosimeter
and the CEL-350IS
dBadge.
Both are designed to be worn by the worker to
collect the noise exposure data during a representative working day.
Operation of both units is identical in terms of running time, memory,
acoustic specifications etc.
How does the new CEL-350 Micro Noise Dosimeter work compared with
regular noise dosimeters?
In a regular noise dosimeter such as the CEL-320
or CEL-360 there is the main body of the meter plus a separate microphone.
The microphone for these types of instruments is on the end of a length of
cable so that the body of the dosimeter is worn on the worker’s belt and
the microphone is placed near the hearing zone. The CEL-350
dBadge Micro Noise
Dosimeter is a complete instrument including the microphone capsule built-in to
the main body of the instrument. As such it is worn on the shoulder or
hardhat as close to the hearing zone as possible.
Is there a separate controller needed for the CEL-350 Micro Noise
Dosimeter?
No. The new CEL-350
dBadge is a completely standalone
instrument that does not rely on any other instrument to see the results.
The only other item needed to use the CEL-350 is a regular standard
acoustic calibrator with a ½” cavity such as the CEL-110/2.
Comparison to existing models
What are the main differences between the new CEL-350 and the existing
CEL-320 and 360?
The existing CEL-320 and CEL-360 models are fully
functional, stand-alone noise dosimeters that have an integral memory and
display with a control keypad. The CEL-350
dBadge Micro Noise Dosimeter is a
simplified version of a logging noise dosimeter yet still includes a display
and some limited external controls for the user. Simplifying the design of
the CEL-350 unit allows a very cost effective dosimeter to be achieved in a
very compact unit.
Does the new CEL-350 Micro Noise Dosimeter replace the existing CEL
dosimeters?
No. The existing CEL-320 and CEL-360 personal noise
dosimeters will continue alongside the new CEL-350 Micro Noise Dosimeter.
The CEL-320 and CEL-360 units can be used for additional types of noise
measurements than can the CEL-350
dBadge that is primarily aimed at Workplace Noise
applications only.
Operation
How does the CEL-350 attach to the operator?
The CEL-350
dBadge is intended to be worn close to the hearing zone therefore
it is supplied as standard with a set of clothing pin clips that can be
attached to overalls or a shirt near the shoulder area.
What other attachment methods are there?
Also provided as standard are a set of alligator
clips. An optional harness and hard hat-mounting clip set is available for use in
areas such as the construction industry or wherever head protection is
mandated.
How long will the standard batteries last in a CEL-350?
The battery pack in the CEL-350
dBadge will last for up to 32 hours running
time. After that running time the instrument will not have enough power to
continue the measurement but it will be able to retain any stored data
safely in the memory until it is recharged again in the approved manner
with the CEL-6350 or CEL-6362 charger units.
How long does the CEL-350 run when powered from the standard
rechargeable battery?
When a completely discharged CEL-350
dBadge Micro Noise
Dosimeter is plugged into a CEL-6350 & CEL-6362 multi-charger units it will be
completely charged in about one and a half hours. A quick 30-minute charge
time is enough to provide a full 8-hour run time for the CEL-350
dBadge. There
is no memory effect with the NiMH battery pack and the dosimeters do not
need to be left on the charger to stay charged although there may be a
small amount of battery leakage over extended periods of time.
Can a rechargeable battery be used in a CEL-350?
Yes, the battery pack in the CEL-350
dBadge consists of 2 half-size NiMH AAA
cells. This set of batteries is hard wired into the instrument and is not
user changeable. A new rechargeable battery pack should be used to replace
the originals in the CEL-350
dBadge Micro Noise Dosimeter when it no longer holds
the charge. This replacement procedure can be carried out during the
normal recalibration process when the instrument is returned to Casella
CEL service laboratory. The rechargeable battery pack in the CEL-350
dBadge is
not normally intended to be a user serviceable item.
Can the CEL-350 be left on the charger when it is fully charged?
Yes, this will not damage the internal battery pack and is the
recommended charging process. The CEL-6350 & CEL-6362 multi-charger units have been
designed to allow up to 3 separate CEL-350
dBadge Micro Noise Dosimeters to be
charged at the same time.
How long will the battery in the CEL–350 hold its charge?
The CEL-350
dBadge Micro Noise Dosimeter will display the amount of running
time available from the battery pack as it is charging.
How often should I recharge the CEL-350?
The CEL-350
dBadge Micro Noise Dosimeter can be safely left for extended
periods of time up to a few months in between charges. It will always
indicate the current battery life remaining whenever switched on so you
will always know what length of measurement can be obtained.
How can the CEL-350 be made tamper proof?
The CEL-350
dBadge Micro Noise Dosimeter can be locked once a run has started
by the supervisor to prevent unauthorized attempts to access the screen
information. This makes the unit particularly safe and secure when used
unsupervised. The run in progress icon and the duration of the run so far
are displayed when the unit is locked out.
How can the CEL-350 be simplified for a specific measurement task?
The design of the CEL-350
dBadge Micro Noise Dosimeter is such that it retains
a single setup configuration in its memory so that it will always perform
the same measurement every time it is used. It is not necessary to choose
from a number of possible setups. There are 2 separate display modes
available from the configuration menu to suit either the US OSHA
regulations or the ISO regulations. This is purely for the display only
since whatever is being displayed the instrument is always collecting the
complete set of results for both OSHA and ISO recordings.
Can the CEL-350 be used for community noise measurements?
The CEL-350
dBadge Micro Noise Dosimeter should not be used for community
noise measurements. The measurement range extends down to 65 dB and
this is often too high for successful environmental noise measurements.
How robust is the CEL-350 Micro Noise Dosimeter?
The CEL-350
dBadge Micro Noise Dosimeter is designed to be robust and to
withstand the wear and tear associated with practical noise measurements
in an industrial environment. It is manufactured using the same material
as is used in many automobile bumpers. One of the main problems with
traditional style noise dosimeters is that the microphone cable can get
damaged or pulled which can then affect the integrity of the measurements
or cause no signal at all to get to the dosimeter. Snagging of the
microphone cable can also lead to possible danger for the employee and so
this is eliminated in the CEL-350. This is not the case with the
instrument since it has the microphone capsule built-in. Also, since the
controls can be locked on the CEL-350
dBadge Micro Noise Dosimeter, the risk of
tampering or misuse is considerably reduced.
What happens if the microphone is damaged?
The CEL-350
dBadge Micro Noise Dosimeter is fitted with a CEL-252 type 2
general-purpose electret microphone capsule. This is screwed into the
input stage of the CEL-350
dBadge and can be easily changed by the user if it
gets damaged in use. The standard CEL-6356 windscreen is provided with
every CEL-350
dBadge to offer some protection for the microphone against the
ingress of wind or dust when in use.
Does pc software come with the CEL-350 Micro Noise Dosimeter?
Yes, the CEL-350
dBadge Micro Noise Dosimeter is supplied with the CEL-6357
dB35 Windows software program that downloads measurements from the
dosimeter to the PC. The measurements can then be viewed and manipulated
with the software using the structure of a database program. Options are
provided to export the data into a spreadsheet for specific reporting and further
analysis. Comprehensive reporting and printing options plus backup and
restore are also available.
I only have a USB port on my computer; can I still download results
from the CEL-350?
Yes, the CEL-350
dBadge Micro Noise Dosimeter has an infrared serial RS232
Output that communicates with the pc via the CMC39 IR interface module to
a 9 way serial connector. Most computers have a suitable 9 Pin RS232 port,
but for those that don't, the CEL-90336 RS232 to USB adaptor is provided
as part of all standard measurement kits.
How long does it take to download a run?
A complete 8-hour shift measurement takes approximately 6 seconds to
download to the pc. A completely full memory of 180 hours of recording
will take just over 2 minutes to transfer to the pc program.
What are the minimum requirements of the pc to run the dB35 software?
Hardware requirements are:
- Pentium III 1 GHz processor
- 128 MByte memory
- 20 GByte hard drive
- CDROM drive for installation
Operating system requirements are:
- MS Windows 2000 with Service pack 4
- MS Windows XP Home or Professional with service pack 2
- MS Windows NT 4 with service pack 6a
Currently the new Windows Vista OS is not completely supported.
Instrument function……
…….SETUP
How many different SETUPs can be stored in a CEL-350?
Only a single setup configuration is stored in the CEL-350
dBadge Micro Noise
Dosimeter for simplicity.
Do I have to select the SETUP each time before a run?
Since a CEL-350
dBadge Micro Noise Dosimeter only has a single setup there is no
need to select it to begin a new measurement run.
How do I change the setup configuration in a CEL-350?
The setup configuration is fixed in the CEL-350
dBadge Micro Noise Dosimeter so it is not necessary to have to change it to make
measurements.
When does a run actually start in a CEL-350?
A new measurement run starts immediately when the Run command is given to
the CEL-350
dBadge Micro Noise Dosimeter.
When does a run actually stop in a CEL-350?
An existing run ends when the CEL-350
dBadge is halted using the buttons on the
side of the unit. Any period data profiles for the unfinished last minute
will not be saved but the overall results will be completely correct for the
calculations of noise dose and TWA and will include this last sub 1-minute
interval.
Are delayed start and stop timers are available in the CEL-350?
It is not currently possible to set delay start and stop timers for a
measurement in the CEL-350
dBadge Micro Noise Dosimeter.
How many runs can be stored in the memory of the CEL-350?
The memory of a CEL-350
dBadge is configured such that any single run will take
at least 1 hour of recording space in the memory. Up to 180 hours of memory
are available in an empty instrument so up to 180 sets of data could be stored
in a CEL-350
dBadge Micro Noise Dosimeter.
How many repeats can be selected in a CEL-350?
No repeats of a run can be selected in a CEL-350
dBadge Micro Noise Dosimeter
since the memory is configured to have manually controlled measurement runs.
Can individual runs be deleted from the instrument?
Yes, the run data stored in the CEL-350
dBadge Micro Noise Dosimeter will be
saved until the erase command is used to clear the memory prior to starting
a new set of measurements. The erase command can be sent from the dB35
software or from the configuration menu in the instrument. All runs stored
in the memory of the CEL-350
dBadge will be deleted at the same time.
How many Threshold levels can be set in the CEL-350?
The data are saved in the CEL-350
dBadge Micro Noise Dosimeter in such a way as
to be able to apply any number of thresholds using the dB35 software after
the runs are downloaded to the pc. Thresholds can be set in 1 dB steps over
the range from 70 to 90 dB. The default is 80 and 90 dB.
What Criterion levels can be set in the CEL-350?
Any criterion level can be selected for the data from the CEL-350
dBadge Micro
Noise Dosimeter once results are downloaded to the dB35 software package.
Criterion values from 70 to 90 dB can be selected in the software in 1 dB
steps. The default is 90 dB.
Are there any alarms available in the CEL-350?
Yes, there are 2 visual alarms available in the CEL-350
dBadge Micro Noise
Dosimeter that use 2 separate high intensity micro LED’s. These are used to
signal warnings for the battery life, memory available and the accumulated
measured noise exposure so far in a run. The function of the Red LED is
shown below and is common to both the OSHA and the ISO display configuration
mode. These are shown below;
|
Red LED |
|
|
| Off |
Flashing slowly on |
On continuously |
| Battery and memory good for > 2 hour recording |
< 2 hours of remaining battery life and memory |
Fatal error, switch off and seek advice from Casella service |
The function of the Blue LED is dependent on the
display mode selected in the instrument configuration menu at switch on.
|
Blue LED |
|
|
|
| Setup for display |
Off |
Flashing slowly every 1.5 sec |
Flashing quickly every 0.5 sec |
| OSHA |
Lavg (Thr=80) <=84.9 dB AND
LZpk <=139.9 dB |
Lavg (Thr=80) >=85 dB OR
LZpk >=140 dB |
Lavg (Thr=80) >=85 dB AND
LZpk >140 dB |
| ISO |
LAeq <=79.9 dB AND
LCpk <=134.9 dB |
LAeq >=80 dB OR
LCpk >135 & <=136.9 dB |
LAeq >85 dB AND
LCpk >=137 dB |
Is it possible to change the alarm levels if future legislation
requires?
Yes, it is possible to change the trigger levels at which the Blue LED
starts to give warnings using the dB35 software package. This is in case the
various noise exposure regulations change during the lifetime of the CEL-350
dBadge dosimeter or if a
customer wishes to use more stringent limits.
Is it possible to disable the alarm function?
Yes, the alarm function can be disabled if it is not required for future
measurement runs using the configuration menu at switch on time. Simply
toggle this function ON or OFF as desired.
The CEL-350
dBadge Micro Noise Dosimeter covers and includes the range from 65 to 140 dB for the measurement of time varying
noise levels.
What happens to noise levels below 80dB(A)?
Any noise level that is below the 80 dB threshold
level is still stored in the dose histograms in the CEL-350
dBadge Micro Noise
Dosimeter and will not be included in the results for the % dose and TWA
calculations shown on the screen. This is in line with the US OSHA
recommendations for noise instruments used for noise dosimetry
measurements. The noise levels are still available when downloaded to the
dB35 pc program for later analysis using different protocols.
How many measurements can be stored with the CEL-350?
Up to 180 measurements can be stored in a CEL-350
dBadge Micro Noise Dosimeter since every run regardless of its actual duration
uses 1 hour of the available memory.
What range does the peak measurement cover?
The range of the peak detector is from 95 to 143 dB for the measurement
of the upper noise limit in situations where the noise climate includes
impact or impulsive sources as required by the US OSHA regulations.
What results can be stored for the whole measurement run?
The CEL-350
dBadge Micro Noise Dosimeter stores the following values;
· the unique instrument ID serial #,
· the run number in the memory,
· the acoustic calibration record pre-run and post-run including date, time and level
offset,
· the start date and time of the run,
· the end date and time of the run,
· the measurement run duration,
· the actual time average level (Lavg) with the Q=5 exchange rate,
· the actual time average level LAeq with the Q=3 exchange rate,
· the measured noise dose % with the Q=5 dB exchange rate,
· the measured noise dose % with the Q=3 dB exchange rate,
· the personal sound exposure level Pa2hr,
· the personal sound exposure level Pa2sec,
· the time weighted average level TWA,
· the personal exposure level LEP,d,
· the sound exposure level LAE,
· the impulse weighted time average level LAIeq,
· the peak level LZpk,
· the peak level LCpk,
· the peak level LApk,
· the A weighted Fast maximum sound level LAFmx,
· the A weighted Fast minimum sound level LAFmn,
· the A weighted Slow maximum sound level LASmx
· the A weighted Slow minimum sound level LASmn,
· the A weighted Impulse maximum sound level LAImx,
· any rms. overload exceedance above 140 dB(A),
· any peak overload exceedance above 143 dB(Z) or dB(C),
· and the battery status.
The CEL-350
dBadge Micro Noise Dosimeter also stores the 4 profiles every 1 minute
including the Q=5 time average level, the unweighted Z peak, the Q=3 time
average level and the C peak level.
What if not all of these parameters are required for a particular
measurement?
It is not possible to disable any of the measured and stored parameters.
They are all measured and collected by the CEL-350
dBadge unit. The dB35 software
allows the results to be limited or included as far as being available and displayed in the
pc after a run.
What rms frequency weightings are available in the CEL-350?
The standardized ‘A’ broadband frequency weighting is provided in the
CEL-350
dBadge Micro Noise Dosimeter as specified in many workplace noise
regulations for the measurement of the dose% and time average levels.
What frequency weightings are available for peak measurements in the
CEL-350?
The standardized ‘Z’, ‘C’ and 'A' broadband frequency
weightings are provided in the CEL-350
dBadge Micro Noise Dosimeter as specified
in many workplace noise regulations for the measurement of the peak
exceedance level.
What time weightings are available in the CEL-350?
The CEL-350
dBadge Micro Noise Dosimeter can have either
the Slow time weighting for US OSHA style measurements or none for
European ISO style measurements where no weighting is specified or the
Fast and/or Impulse time weighting for some of the measured values.
What exchange rates or Q values are available in the CEL-350?
The CEL-350
dBadge Micro Noise Dosimeter has both the Q=5
dB exchange rate for US OSHA style measurements and Q=3 (equal energy
principle) for European ISO style measurements at the same time in every measurement run.
How can the calculation of LEP,d be made for non-standard working
days?
The European ISO style unit LEP,d for non-standard
working days may be calculated using dB35 once the
measurement run and time
history profiles have been transferred to the computer.
How can the calculation of TWA be made for non-standard working days?
The US OSHA style unit TWA for non-standard
working days may be calculated using dB35 once the
measurement run and time
history profiles have been transferred to the computer.
What is the difference between LEP,d and LEP,v?
The unit LEP,d is always calculated based on a
standard time interval of exactly 8 hours whereas the LEP,V unit can be calculated for any
other time interval of not exactly 8 hours.
What is the difference between TWA and TWA,v?
The unit TWA is always calculated based on a
standard time
interval of 8 hours whereas the TWA,v unit can be calculated for any other
time interval of not exactly 8 hours.
…….TIMERS & RUN LENGTH
What time intervals are available for measuring the profiles in the
CEL-350?
A single fixed time interval of 1 minute is
available for measuring the time history profiles in a CEL-350
dBadge Micro Noise
Dosimeter. This is the best compromise for simplicity and detail for most
noise dosimetry measurements giving adequate time resolution for later
calculations in software when necessary for “what if?” purposes.
What fixed durations are available for the overall run time in the
CEL-350?
Run times are controlled manually by the user of
the CEL-350
dBadge Micro Noise Dosimeter so do not currently have any fixed times
associated with them.
Can the measurement be synchronized to the real time clock?
No. Measurements begin as soon as the start run
key is pressed on the CEL-350
dBadge Micro Noise Dosimeter. Results for the time history profiles
are shown to the nearest minute when downloaded to dB35.
What is the shortest run duration that can be stored in the CEL-350?
The shortest measurement run that can be stored
in a CEL-350
dBadge can be as little as a minute. However, it is recommended that longer
measurements be carried out to obtain a representative period of recording
covering all of the significant sources of noise in the workplace
situation.
What is the longest run duration that can be stored in the CEL-350?
The longest run duration is linked to the
operational life of the battery in the CEL-350
dBadge Micro Noise Dosimeter. This
is in the order of 32 hours.
Accuracy and results
What standards and accuracy is the instrument designed to fulfill?
The CEL-350
dBadge Micro Noise Dosimeter has been
designed to meet the requirements of ANSI S1.4 1991 when configured in the
OSHA setup and IEC 61252:2002 when configured for ISO setup. It also meets
ANSI S1.25 1991 when used as a Noise dosimeter or for Personal Noise
Exposure Meters.
Is the CEL-350 certified Intrinsically Safe for use in hazardous
areas?
Yes, (as from May 2007). The original version of
the CEL-350
dBadge Micro Noise Dosimeter is not suitable for use in hazardous
environments, which require UL or an Eex or ATEX certification. However, an
intrinsically safe version called the CEL-350IS
dBadge Micro Noise Dosimeter has now been released for sale. FM approval is
now also available (as from October 2007) specifically for the North American market
(US and Canada certifications approved).
How often does the CEL-350 need to be recalibrated?
As with all noise measurement equipment, the
CEL-350
dBadge Micro Noise Dosimeter and CEL-110/2 Acoustic calibrator should be
recalibrated at least every 2 years. The CEL-350 Micro Noise Dosimeter and
CEL-110/2 Calibrator should be recalibrated together as they are used as a
set. Instruments should be returned to the manufacturer for a traceable
recertification each year or as the local regulations require.
What results can be calculated and displayed?
Although it is not a direct reading sound level
meter the CEL-350
dBadge does have an integral display that is used to display a
certain limited set of data depending on whether the OSHA or the ISO mode
has been selected from the configuration menu for the unit.
In the OSHA mode the following limited
items are displayed to give the user a degree of confidence that the
readings are as expected.
·
Remaining memory time
·
Remaining battery life
·
Current time
·
Current Slow weighted sound pressure level
·
Duration of the current run in hh:mm:ss
·
The time average noise level with the Q=5 exchange rate in
dB
·
The Z weighted peak noise level in dB
·
The actual noise dose% with a threshold of 80 and a
criterion of 90 dB plus the 8 hour projected noise dose %
In the ISO mode the following items are
displayed;
·
Remaining memory time
·
Remaining battery life
·
Current time
·
Current Slow weighted sound pressure level
·
Duration of the current run in hh:mm:ss
·
The time average noise level with the Q=3 exchange rate in
dB
·
The C weighted peak noise level in dB
·
The sound exposure level in Pa2hr
How many runs can be stored in a CEL-350 Micro Noise Dosimeter?
The CEL-350
dBadge Micro Noise Dosimeter stores up to 180
runs. The duration of these runs can be any length but the data logging of
the Time History Profiles of 1-minute data is fixed at a maximum of 32
hours due to the battery life consideration. This data is always stored as
four separate profiles at 1-minute intervals and includes;
·
The time average level (LAvg) with the Q=5 exchange rate in
dB
·
The time average level (LAeq) with the Q=3 exchange rate in
dB
·
The Z weighted peak level in dB
·
The C weighted peak level in dB
·
Any Overload flags for the period
How many profile points in total can be stored in the CEL-350?
There is storage space in the CEL-350
dBadge for 64kbytes
of data. This is allocated as shown below.
·
4 profiles every 1 minute
·
240 profiles per hour
·
Maximum of 180 hours memory allocation
·
43,200 profile points for a completely full memory
How many profiles can be stored in a single run in a CEL-350?
The battery life of a CEL-350
dBadge Micro Noise
Dosimeter is 32 hours so at 1-minute intervals a single run can
store the results for about 32 x 60 x 4 = 7600 time history profiles.
How long does the memory last when recording profiles in a CEL-350?
At the end of the normal 32 hour battery life of a
CEL-350
dBadge Micro Noise Dosimeter when the power supply is too low to continue
with measurements there is still enough power to maintain the contents of
the memory for long enough to be able to download to the dB35 software
package. All run data will be saved and the dosimeter will switch itself
off safely to preserve the recorded values.
What happens if the battery pack runs down during a measurement?
Run data are stored in a non-volatile E2
ROM chip that does not require a backup battery to hold the
measurements. If the battery pack runs out during a measurement then all
the results up to the last full minute will be saved and the CEL-350
dBadge will
shut down in an orderly fashion and no data will be lost.
The standard warranty for the CEL-350
dBadge Micro Noise
Dosimeter is 12 months parts and labor from the date of receipt of the
instrument. After the first 12 months the Casella USA main office in
Amherst, NH will handle the recalibration and any repairs that may be
necessary. Extended warranty is available from Casella USA for the
dBadge dosimeters.
Please contact the sales office for full details.
Applications
What markets are the instruments designed for?
The primary market for the CEL-350
dBadge Micro Noise
Dosimeter is for industrial hygiene measurements to make assessments of
workplace noise exposure. This would be to satisfy the OSHA regulatory
body that any individuals in a workplace are being subjected to excessive
amounts of noise beyond the legal limits specified in 29 CFR Occupational
Noise Exposure 1910-95. Since the CEL-350
dBadge stores data with both the Q=5
and Q=3 exchange rates simultaneously it is also possible to satisfy the
recommendations of NIOSH and ACGIH from a single measurement run.
How does the CEL-350 cater for these markets?
Although there are many types of noise dosimeters
available both from Casella CEL and from other manufacturers the CEL-350
dBadge offers a significant addition to the capabilities of many users who have a
need for multiple noise dosimeters for workplace noise assessments. The
unit costs of more than 2 or 3
dBadge Micro Noise Dosimeters start to become very
attractive for larger and larger kits when compared to conventional
dosimeters.
Since a single CEL-350
dBadge Micro Noise Dosimeter does not require
any specialized reader unit to retrieve the data it can be used on its own
and it is very easy and cost efficient to add more CEL-350
dBadge dosimeters to a
system in order to cover large numbers of workers.
The standard software
package, called dB35, provides a very easy yet powerful download and
reporting system to keep track of all the relevant details of all the
measurements undertaken with a CEL-350
dBadge Micro Noise Dosimeter system. The
results from stored recordings can be sorted by applying filters depending
on the noise exposure levels and printed very quickly and easily.
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