Casella CEL-960 User manual

CEL-960 Human Vibration Meter
HB4040-01
User Manual
CASELLA MEASUREMENT
Regent House,
Wolseley Road,
Kempston,
Bedford,
MK42 7JY, U.K.
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
Web: www.casellameasurement.com
User Manual

CEL-960 Human Vibration Meter
2 Casella CEL
Contents
Contents ........................................................................................................................................... 2
1General .............................................................................................................................. 5
1.1 Introduction ...................................................................................................................... 5
1.2 Major functions................................................................................................................. 5
1.3 Displayed Values .............................................................................................................. 6
1.3.1 Measured.......................................................................................................... 6
1.3.2 Additional......................................................................................................... 6
1.3.3 Alarm indicators ............................................................................................... 6
2Layout of the CEL-960 Instrument.................................................................................... 7
2.1 Connections ...................................................................................................................... 7
2.1.1 Transducer connector....................................................................................... 7
2.1.2 Charger / Download connector ........................................................................ 7
2.2 LED’s ................................................................................................................................. 8
2.2.1 Measurement (On/Off) LED .............................................................................. 8
2.2.2 Wireless communication LED........................................................................... 8
2.2.3 Battery LED....................................................................................................... 8
2.2.4 Alarm LED......................................................................................................... 8
2.3 On/Off key ......................................................................................................................... 9
2.4 Charging the battery....................................................................................................... 10
3Using the CEL-960 in stand-alone mode.......................................................................... 11
3.1 Introduction .....................................................................................................................11
3.2 Calibration of CEL-960..................................................................................................... 11
3.3 Measurement mode .........................................................................................................11
3.4 Data reading mode.......................................................................................................... 11
4Using the CEL-960 with a PDA........................................................................................ 12
4.1 Introduction .................................................................................................................... 12
4.2 General operation ........................................................................................................... 12
4.2.1 General points................................................................................................ 12
4.2.2 Menu bar ........................................................................................................ 13
4.3 Implementation............................................................................................................... 13
4.4 Main screen..................................................................................................................... 14
4.4.1 Input of the Licence Number ......................................................................... 14

CEL-960 Human Vibration Meter
3 Casella CEL
4.4.2 Creation / Editing / Deletion of a ‘Workshop’ ............................................... 14
4.4.3 Assignment / Removal of a CEL-960 to/from a ‘Workshop’ ......................... 15
4.4.4 Reading / Writing of time and date............................................................... 16
4.5 Configuration management screen................................................................................. 16
4.5.1 Measurement configuration screen ............................................................... 17
4.5.2 Start-up configuration screen ........................................................................ 21
4.5.3 System configuration screen ......................................................................... 24
4.6 Measurement mode ........................................................................................................25
4.6.1 Measurement screen......................................................................................26
4.7 Measurement stop.......................................................................................................... 29
4.8 Transfer / Deletion of files..............................................................................................30
4.8.1 Transfer via Bluetooth ...................................................................................30
4.8.2 Transfer via USB on PC.................................................................................. 33
4.8.3 Deletion .......................................................................................................... 33
4.9 Reading data stored on the PC...................................................................................... 34
4.10 Secondary functions .......................................................................................................36
4.10.1 Connection .....................................................................................................36
4.10.2 Disconnection................................................................................................. 36
4.10.3 Calibration of CEL-960 ................................................................................... 37
4.10.4 Measurement start .........................................................................................39
4.10.5 Measurement stop .........................................................................................40
4.10.6 Rename the instrument ................................................................................. 40
4.10.7 Factory configuration .....................................................................................40
4.10.8 Auto Test........................................................................................................ 41
4.10.9 SDCard memory formatting ...........................................................................42
4.10.10 Reading of transducer characteristics ...........................................................42
4.10.11 Creating a transducer..................................................................................... 43
4.10.12 Updating the firmware ................................................................................... 43
5Using the CEL-960 with a PC.......................................................................................... 45
5.1 Bluetooth communication ..............................................................................................45
5.2 Launching software dB96 on the PC.............................................................................. 45
5.3 Implementation...............................................................................................................45
5.4 Data transfer ................................................................................................................... 46
5.4.1 Data transfer via Bluetooth ...........................................................................46

CEL-960 Human Vibration Meter
4 Casella CEL
5.4.2 Data transfer via USB..................................................................................... 46
6dB96 System errors......................................................................................................... 48
7Technical specifications................................................................................................... 50
7.1Standards........................................................................................................................50
7.2 Metrology ........................................................................................................................50
7.3 Memory module.............................................................................................................. 51
7.4 Battery............................................................................................................................. 51
7.5 Physical characteristics................................................................................................... 52
7.6 Comment on the influence of the electromagnetic environment..................................52
8Maintenance ....................................................................................................................53
8.1 Auto-Test......................................................................................................................... 53
8.2 Disposal ..........................................................................................................................53
9Icons used in dB96 Control Software ............................................................................. 54
10 Glossary of terms & formulae.........................................................................................55
10.1 Terms ..............................................................................................................................55
10.2 Formulae .........................................................................................................................55

CEL-960 Human Vibration Meter
5 Casella CEL
1General
1.1 Introduction
The CEL-960 is a unique concept in the measurement of human vibration since,
unlike other instruments, the person making the measurement can stand remotely
from the subject being monitored and thus not interfere with their work, which
makes it particularly ideal for mobile operatives such as fork lift truck drivers.
It is capable of measuring Hand Arm (HA) or Whole Body (WB) vibration
depending upon the transducer connected i.e. triaxial accelerometer or seat pad, in
either broad band or 1/3rd octaves, again depending whether the latter option has
been purchased.
It meets all the relevant International standards and is further differentiated from
other instruments through it‟s innovative user interface. The CEL-960 has just one
control switch and a small number of LEDs to indicate status, the main control
being performed by software (dB96) which wirelessly connects to the CEL-960 and
runs on a PDA or more typically a laptop PC.
The software allows the instrument to be set up in a so-called workshop, a
measurement to be initiated and results to be viewed in real-time and subsequently
stored. Up to 5 instruments may be controlled in this way. The data may be
downloaded to a spreadsheet or viewed and manipulated in an optional software
package, dB98.
1.2 Major functions
3 Types of measurements:
oHand arm (frequency) weighted measurements (as per ISO5349 & ANSI
2.70)
oWhole body (frequency) weighted measurements (as per ISO2631 &
ANSI 3.44)
oUnweighted „free‟ measurements
Parallel vibration measurement:
oRMS acceleration: a (x, y, z), aw (x, y, z).
oPeak and peak-to-peak acceleration: apk (x, y, z), awpk (x, y, z).
oPeak factor: fc, fwc.
oEquivalent acceleration: ahv, av, aeq.
Calculation of indicators depending on the configuration:
oA(8), A(8)v.
oVDV, MTVV.
Alarm management:
oExceeding vibration level threshold.
oOperating status (battery, memory).
Advanced customisation of calculations, display and storage:
oType of measurement.
oT0: reference duration.
oIntegration time.

CEL-960 Human Vibration Meter
6 Casella CEL
oTime constant.
oAlarm threshold.
Possibility to program measurement in terms of starting date and duration
(3 different modes):
oImmediate.
oDelayed.
oOn a presence detector (with the WB transducer only)
Large storage capacity (1 GB flash memory).
Long battery operating life.
“Bluetooth®wireless technology” communication.
Event coding (2 dedicated keys).
Audio recording.
Oral and/or written comments.
Protecting function against accidental shutdown resulting from erroneous
action.
Pre-test function ensuring quick a check-up of operations.
1.3 Displayed Values
1.3.1 Measured
a: Band Pass acceleration
aw: Weighted acceleration (Wd, Wh, Wk filter)
apk: Band Pass peak acceleration
apk-pk: Band Pass peak-to-peak acceleration
apk: Weighted peak acceleration (Wd, Wh, Wk filter)
apk-pk: Weighted peak-to-peak acceleration (Wd, Wh, Wk filter)
fc: Band Pass peak factor
fwc: Weighted peak factor (Wd, Wh, Wk filter)
ahv: Hand Arm resulting acceleration
av: Whole Body resulting acceleration
aeq: Whole Body resulting acceleration
A(8): Hand Arm or Whole Body daily exposure
A(8)v: Whole Body daily exposure
VDV: Whole Body vibration dose
MTVV: maximum transient vibration: maximum value for the mobile RMS
value of the vibration acceleration when the integration time is 1 s.
1.3.2 Additional
Measurement duration
Operating life for measurement
1.3.3 Alarm indicators
Overload and under-load indicator
Alarm indicator
Battery indicator

CEL-960 Human Vibration Meter
7 Casella CEL
2Layout of the CEL-960 Instrument
Figure 1. Main features of the CEL-960 Vibration meter
2.1 Connections
2.1.1 Transducer connector
The chosen transducer (HA or WB) is connected via the Lemo connector located on
the top of the instrument. The plug will only fit one way and a red dot on the
connector pair will aid alignment.
In the case of the tri-axial accelerometer, where possible it must be directly attached
to the tool or machine under investigation or alternatively securely attached using
the most appropriate fixing supplied e.g. V-Block and nylon cable ties. If in any
doubt, refer to guidance given in ISO 5349-2 and/or seek advice from a relevant
agency e.g. HSE in the UK, NIOSH in the US.
2.1.2 Charger / Download connector
A USB-type connector is used to charge the CEL-960 with the charger provided (see
section 2.4). It is also be used to read the internal memory.
Connector for HA
or WB transducer
Wireless
communication
LED (displays
blue)
Battery LED
(displays red or
green)
USB Connector
(not shown)
Measurement
(On/Off) LED
(displays red or
green)
Alarm LED
(displays
red when
activated)
On/Off key

CEL-960 Human Vibration Meter
8 Casella CEL
When the USB connection is active, the Bluetooth communication is disabled.
2.2 LED’s
The LEDs provide information on the operating status of the CEL-960 instrument
as shown in the diagram overleaf. They can be disabled by the PC in order to save
battery life.
2.2.1 Measurement (On/Off) LED
This two-colour green/red LED shows the status of the CEL-960:
Permanently green: instrument is ON.
Fast blinking green: measurement has started.
Green blinking once every second: instrument is in measurement and
storage mode.
Permanently green: displayed at the end of measurement and if
measurement completed correctly.
Permanently red: displayed if measurement stopped abnormally (battery
problem, full memory). See Chapter 6 for details of system errors.
Permanently red (at start): low battery or insufficient memory.
Blinking red: low battery during measurement.
2.2.2 Wireless communication LED
This blue LED shows the status of the wireless connection:
Permanently lit: Bluetooth connection is active.
Blinking: Activity is detected on the network.
2.2.3 Battery LED
CAUTION: this light indicator is the only one that is not managed by the
instruments processor but directly by the charger integrated into the CEL-960
instrument. It lights up as soon as the charger is connected to the CEL-960. It is:
Permanently green during the charging process (turns off at the end of the
process).
Red if charging error (faulty battery, excessive temperature, power supply is
too weak).
2.2.4 Alarm LED
This red LED is located on the top of the housing so as to be visible by the wearer
and shows particular vibration events:
Overload on the input signal of a transducer.
Exceeding a dose or programmed threshold.

CEL-960 Human Vibration Meter
9 Casella CEL
At start up, this LED lights up and turns red if the previous measurement stopped
abnormally (full memory or low battery).
During the self test, the alarm LED is on and the red “on/off” LED blinks during the
stabilising phase (10s), then turns green and keeps blinking during the
measurement (5s). This sequence is repeated 4 times.
2.3 On/Off key
This key can be used to trigger several actions depending on the status of the
instrument:
The CEL-960 is “Off”: slightly pressing this key will set the instrument in
stand-by mode, the measurement (On/Off) LED is active and green.
The CEL-960 is “Off”: pressing the On/Off key for about 3 s will set the
instrument in measurement mode (immediate start) with the current
measurement configuration i.e. that stored previously. The measurement
(On/Off) LED lights up permanently from the moment the key is pressed
down, and then blinks rapidly as the measurement starts. During the
measurement, the LED blinks once every second.
If, in the configuration, the LED has been deactivated during measurement, it will
stop blinking after 30 s. Briefly press the key to reactivate the LED for 1 minute.
The CEL-960 is in stand-by mode: press the On/Off key for more than 5s to
stop the instrument.
The CEL-960 is in measurement/storage mode and in discreet mode (the
LED is disabled during the measurement): briefly press the On/Off key to
reactivate the LED during 1 minute.
The CEL-960 is in measurement and storage mode (the Bluetooth
connection is deactivated): press the on/off key for 2 s to reactivate the
Bluetooth communication during 1 minute.
The CEL-960 is in measurement and storage mode (non deactivated key):
press the On/Off key for more than 10s to stop the instrument.
The CEL-960 is in measurement/storage mode: pressing the On/Off key will
have no effect if the key has been deactivated. In order to stop the
measurement, one must take control using the PC or wait for the battery to
be discharged or for the measurement to be completed if automatic stop has
been programmed. However, pressing the On/Off key 10 times with the
same frequency as that of the blinking of the green LED will stop the
instrument.
When the CEL-960 is shut down, the Alarm LED blinks red for 5 seconds. Pressing
the key for 2 seconds will reactivate the Bluetooth connection during 5 minutes,
thus allowing taking control of the instrument with a PC.

CEL-960 Human Vibration Meter
10 Casella CEL
2.4 Charging the battery
When the battery is low, the On/OFF LED lights up in red, meaning that the battery
needs to be recharged.
Also, if when sending out a measurement configuration, the end date and time for
the measurement do not correspond to those expected and if the available memory
size is large enough, the battery needs to be recharged. To do so, connect CEL-960
to the charger base. The Battery LED lights up in red upon connection, then turns
green indicating that the charging process has started and is in progress.
After 3 hours, the charging is finished and the Battery LED turns off: the battery is
now correctly charged.
It is also possible to charge the battery using the USB cable but the charge may be
incomplete. This results from the voltage drop in the cable, which varies depending
on the cable. If the charging process is not completed after 7 hours, the LED will
light up in red.
If the battery is already charged when it is connected to the charger, the LED will
light from red to green and then turn off after a few minutes.
If the LED remains permanently red it means that a problem was detected during
the charging process. It may be an abnormally discharged battery, which cannot
then be recharged, or a charge voltage that is too low, or excess battery heat-up.

CEL-960 Human Vibration Meter
11 Casella CEL
3Using the CEL-960 in stand-alone mode
3.1 Introduction
Although the CEL-960 has been designed to be operated coupled with a PDA or PC
that acts, as the user interface, it can be used in stand-alone mode. In this case, the
CEL-960 can perform measurements and store them, according to the
measurement configuration previously used.
The key on the front panel is used for:
Power up
Immediate start of the measurement
When the CEL-960 is powered up, the “On/Off” LED lights up in green if the
instrument does not detect any operating defect. If a problem is detected when the
instrument is started, the LED lights up in red indicating that a problem was
encountered. The measurement will not start until the problem is resolved.
The “Battery” LED remains off as long as the battery has not reached its recharging
threshold and can thus still perform measurements for some time.
3.2 Calibration of CEL-960
No calibration can be performed in the stand-alone mode. A PC is required for this
operation.
3.3 Measurement mode
Pressing the « On / Off » key for 5 seconds will start the measurement. The LED
blinks rapidly while the CEL-960 stores values defined in the configuration
memorised last, according to the defined integration time. After a time out of 10 s
(stabilisation time for the measurement system), the green LED (on/off) blinks once
every second, indicating that CEL-960 is in measurement and storage mode.
The measurement stops:
By pressing (10s) on the « On / Off » key
When the battery is empty
When the memory is stopped
When the measurement is stopped using the keyboard, the « On / Off » LED blinks
red for 5 s before stopping of the instrument.
Even if the instrument stops the measurement after detecting low battery or full
memory, the measurement file is still closed before shutdown.
For this type of operating mode (start from the keyboard), the time start
configuration is ignored.
3.4 Data reading mode
In stand-alone mode, data must be transferred to the PDA or to a PC for further
analysis. Please refer to Chapters 4 & 5.

CEL-960 Human Vibration Meter
12 Casella CEL
4Using the CEL-960 with a PDA
4.1 Introduction
This is the most advanced operating mode for the CEL-960, which gives it
unrivalled power and user-friendliness required to study occupational vibration.
The PDA is used to set up the CEL-960 in a „workshop‟, then to monitor up to five
instruments simultaneously.
A full list of icons used is shown on Section 9.
Where a PC is used instead of a PDA, please refer to Section 5, which shows the
differences in operation.
4.2 General operation
4.2.1 General points
The different icons are as universal as possible and all basic actions can be accessed
directly from each screen. Only functions that are specific to a particular instrument
require a specific action: use of the stylus on the area representing the instrument.
This can be compared to the “right click” of a PC mouse.
A keyboard is displayed at the bottom of the screens where text input is possible.
The user can enter the text using the stylus. Clicking on the keyboard icon
will show or hide the keyboard.
In the list of CEL-960s assigned to a „workshop‟ (right side of the screen), an
instrument icon is displayed and information corresponding to this instrument
is also displayed i.e. the serial number.
On the virtual keyboard, one can switch from the alphabetic to the numeric
keyboard by clicking on the key.

CEL-960 Human Vibration Meter
13 Casella CEL
4.2.2 Menu bar
This bar, which is displayed in all screens, is used to switch rapidly from one screen
to another.
Access to „workshop‟ management
Access to measurement and storage parameters
Access to real-time display of vibration indicators
F (fast), S (slow)
Access to data transfer function from CEL-960 to the
PC
Access to results screen
4.3 Implementation
When the software program is started for the first time, the user is prompted for a
licence number, which will allow unlocking operating modes and options. The
software will not operate without this number.
After launching the dB96 program, the user must „search‟ for the CEL-960(s)
present in the wireless communication range using the key.
The communication range is about 10 m for a PDA equipped with class-2 Bluetooth.
Icon shows this activity. When this implementation phase is finished, the
„workshop‟ management screen is displayed.

CEL-960 Human Vibration Meter
14 Casella CEL
4.4 Main screen
This screen is used to organise measuring instruments based on the operator‟s
requirements:
Assignment of a name to a „workshop‟ when it is created and input of a brief
description.
Deletion of a „workshop‟ from the list.
Assignment of 1 to 5 CEL-960s to the „workshop‟.
Deletion of one or several CEL-960s from the „workshop‟.
Reading of the date and time of a CEL-960 instrument.
Date and time setting of all CEL-960 instruments in the „workshop‟.
Input of the licence number.
The left part of the screen shows the list of instruments that can be assigned to the
„workshop‟ (this list is built up as CEL-960 instruments are detected in the
immediate surroundings of the PDA). Already assigned instruments are listed in the
right part of the screen.
4.4.1 Input of the Licence Number
The operator must first enter the licence number corresponding to the options
available on CEL-960 by clicking on .
4.4.2 Creation / Editing / Deletion of a ‘Workshop’
Click on the creation icon to create a new „workshop‟. An input keyboard is
available at the bottom of the screen. The operator can enter the name of the
„workshop‟ and add a comment, e.g., a technical description.
Instrument
10017 is
assigned to
the workshop
2 CEL-960 are
detected and
waiting to be
assigned

CEL-960 Human Vibration Meter
15 Casella CEL
This keyboard is also available when an existing „workshop‟ is edited by using icon
. When the input or the editing is finished, the operator selects the validation
icon or the cancellation icon to quit this screen without the changes.
A „workshop‟ can be deleted from the list by displaying its name in the window and
selecting the icon. A confirmation is always requested to avoid any error.
Creation, editing, deletion procedures are the same for all screens („workshop‟,
configuration).
4.4.3 Assignment / Removal of a CEL-960 to/from a ‘Workshop’
Once an instrument is selected in the list on the left (click on the CEL-960 serial
number to select it), the operator can assign the instrument to a „workshop‟ as
follows:
Selecting icon will transfer the selected instrument from the list on the left to
the „workshop‟, the name of which is displayed (list in top right corner of the
screen).

CEL-960 Human Vibration Meter
16 Casella CEL
Selecting icon will remove the selected instrument from the „workshop‟ and
place it in the list on the left. CEL-960 no longer appears on the top right of the
screen.
4.4.4 Reading / Writing of time and date
At any time, the operator can read the date and time of the selected CEL-960
instrument exposure meter, which is marked by icon , by clicking on icon .
Before starting a measurement, the operator can even send the date and time of the
PC to all Instruments by clicking on icon .
4.5 Configuration management screen
The configuration of the CEL-960‟s assigned to the „workshop‟ is achieved from this
screen using icon .
User-selected parameters are then transferred to one or several instruments. The
user can also retrieve the internal configuration of a selected instrument.
The user can create, edit or delete 3 types of configurations:
The measurement configuration (3 types of measurements are possible:
whole body, hand arm, free).
The start-up configuration.
The system configuration.
Editing, creation and deletion icons perform the same functions as those in the
„workshop‟ screen.

CEL-960 Human Vibration Meter
17 Casella CEL
4.5.1 Measurement configuration screen
Suited to the CEL-960 operating mode (whole body, hand arm, free), this screen is
more or less detailed depending on the presence of the audio and spectrum option.
Some of these screens below are only available in CEL-960 Expert.
The “Measurement configuration” screen includes several tabs:
Configuration of the measurement.
Configuration of displayed and stored overall results.
Alarm configuration.
Configuration of the sampled signal recording (option).
4.5.1.1 Configuration of the measurement
This configuration of the parameters of the instrument allows selecting, depending
on the type of measurement:
Type of accelerometer.
Measurement unit.
Coefficients used in the calculation of indicators av, ahv.
Integration time.
Time constant.
Standardised duration T0 for the work station.
Real-time display frequency for indicators.
Channel and type of filtering (octave, 1/3 octave) on this channel (option).
Limits of the analysis band in free mode
The Time constant parameter is only used in the whole-body measurement, in
indicator MTVV.
The signal recording channel must be the same as the spectrum calculation channel.
If box “Display at IT” is checked, results are refreshed every integration time,
otherwise every second.

CEL-960 Human Vibration Meter
18 Casella CEL
If the keyboard hides the table bottoms, the user can click on the keyboard icon
, so that the keyboard is minimised and the hidden parts are shown.
4.5.1.2 Configuration of measurement results
This part of the measurement configuration allows the operator selecting only
results that he/she wants to see displayed and stored.
This confirmation is confirmed by clicking on the validation icon.
Storage of IT per axis: RMS and peak values stored at each integration time,
either in “broad band”, or weighted.
Storage of multi axis IT: Values resulting from calculation over the 3 axes and
stored at each integration time.
Note: the spectrum is calculated on a single axis.
Storage of global results per axis: Global values calculated on each axis, over
the total measurement time.
Storage of global multi axis results: Values calculated over the measurement
time and taking into account the 3 measurement axes.
At the end of the measurement, only selected indicator will be displayed on and
stored in the PC as a text file.
4.5.1.3 Configuration of alarms
The Alarm LED will be triggered if one of the conditions presented below is fulfilled.
These conditions are different depending on the type of measurement: whole body,
hand arm or free.
If the operator decides not to set any alarm condition, the option “Never” must be
selected.

CEL-960 Human Vibration Meter
19 Casella CEL
The different triggering options are as follows:
Overload: as soon as the vibration signal overloads, CEL-960 indicates it by
activating the LED.
Exceeding A(8): as soon as the exposure level A(8) is exceeded, the alarm
LED is activated.
Exceeding A(8)v: the LED is activated as soon as the A(8)v level is exceeded.
This alarm exists only for whole body measurements. Please refer to the
definition of A(8) and A(8)v for more details.
Exceeding VDV: the operator can request the activation of the LED when
VDV exceeds the alarm level.
In case of a whole-body measurement and when using the seatpad transducer
(equipped with a presence detector (see section 7.2.), this screen allows selecting
the operating mode for the detector:
None: the operating mode does not take the presence detector into account.
This option is selected if one does not want to use this detector or if the
transducer is not equipped with this detector.
Coding (Marking of data): if this option is selected each time the presence
detector is no longer active (i.e., the operator leaves the seat or if he/she
stands up) recorded data will be coded (marked).
Deletion and coding: if this box is checked, the non presence of the operator
on the seat will lead to the coding of stored values and the affect acquired
data.
In this case, the real-time results screen will display the calculation time in addition
to the measurement time. It corresponds to the total measurement time minus the
periods of non presence of the operator on the seat.
The artefact counter (non presence of the individual on the seat) is incremented
every second.

CEL-960 Human Vibration Meter
20 Casella CEL
4.5.1.4 Configuration of the audio recording (option)
The recording of the vibration signal is an option that is available in whole-body,
hand-arm and free mode.
In the configuration screen, the operator can select:
The sampling frequency ranging from 256 Hz to 8192 Hz.
The acquisition channel: the signal can only be recorded for the channel
used to calculate the spectrum.
The pre-trigger time, which is the time before the event recorded when the
recording is triggered on threshold. The maximum value of the pre-trigger
depends on the calibration frequency: 0 s for 8192 Hz, 1 s for 4096 Hz…. 16 s
at 256 Hz, etc.
The post-trigger duration: when the recording of a signal is triggered on
threshold after the values goes below the threshold, the signal keeps being
recorded during this time.
The maximum recording time: the recording time is limited to a maximum
value in order not to fill the memory. This means that if one selects 20 s and
if the threshold exceeds 5 minutes, the maximum recording time will be the
pre-trigger duration + 20 s + the post-trigger duration.
The triggering type:
oManual: The operator activate the signal recording, according to its
needs (click on icon ).
oOn limit value: As soon as the programmed limit value is reached,
the recording is activated or stopped, taking into account the pre-
trigger/post-trigger parameters and the maximum duration.
The limit value can be chosen on:
Band pass (unweighted) acceleration.
Acceleration with Wh, Wd, Wk frequency weighting.
A spectrum band 1/1 octave or 1/3 octave if a spectrum is selected in the
measurement configuration.