Ono Sokki CF-7200 Reference guide

ONO SOKKI CO., LTD.
CF-7200 Portable FFT Analyzer
Noise analysis procedure

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CF-7200 Portable FFT Analyzer
Noise analysis procedure
To perform noise analysis by using the AC out terminal of the sound level meter, operate unit calibration to enable reading
the same unit as the sound level meter. This document describes the simple calibration method using the CAL signal [1
kHz, 94dB] from the sound level meter. This document also describes the simple method of power spectrum averaging
measurement, octave display, and 3D display. The unit calibration in this document, the analog output of the sound level
meter is connected to the CH1 of the CF-7200 and the level range is selected as 100 dB.
Throughout this document, the name of any soft key on the screen will be presented in square brackets (e.g., [MAIN]), and
the name of any operation button on the panel will be enclosed by single quotation marks (e.g., 'START'). In the text, "key"
means a soft key on the screen and "button" means an operation button on the panel.
■ System Configuration
Microphone of the sound level meter
AG-2000 series
Microphone extension cable
Microphone of the sound level meter
Sound Level Meter
CH 1
AX-501 Output cable

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■ Operation Flow
■ Buttons on Operation Panel
Change the Y-axis scale
Y: LOG/LIN
AVE (averaging)
START/STOP/PAUSE
SAVE/LOAD
Set to CH1 SPECT (spectrum)
Change the voltage range of CH1
FREQ (frequency range)
Power switch ON
[1] Input the CAL signal of the Sound Level Meter
[2] Turn on the START button
[3] Display the spectrum
[4] Setting the voltage range and frequency range
[5] Unit calibration
[6] Measurement and averaging
[7] Dual window display
[8] Octave display
[9] Data reading by search-Peak list
[10] Saving data
[11] Reproducing data
[12] Copying saved data to a USB memory device
[13] 3D display
[14] Useful functions

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■ Operation Procedure
1．Power ON
Press and hold the POWER switch for at least 1 second.
When turning off power, similarly press and hold the power button.
-1. Press the keys in the order [MAIN]> [MEMORY]> [PANEL COND]> [INITIALIZE].
①②③
When the "Yes No" screen is displayed, press "Yes". After a while, the screen will be set up in the default
configuration and the data will be displayed.
-2. Press the 'START' button on the operation panel to set it in the measuring mode. The lamp on the button
will turn on. When any setting is changed, the screen will be promptly updated, facilitating checking of the
setting results.
2．Connecting the Sound Level Meter
Connect the analog output of the sound level meter to the CH1 of the CF-7200 and select C-weighting, then
press CAL button of the sound level meter.
The sound level meter outputs the internal calibration signal. The CAL signal of the sound level meter is
frequency 1 kHz in general. The signal of -6dB is outputted according to the upper limit value of the selected
level range and the dB value of it is displayed. The level range of the sound level meter is selected as 100dB, so
-6dB of it is 94dB. The unit calibration of the CF-7200 is to match the overall value of the power spectrum and
the displayed value (94dB) on the sound level meter.
Notes:
When 1 kHz of calibration signal (sine wave) is used for the calibration, the calibrated value are the same
whichever of the frequency weighting of A, C or Z (flat) is selected. This is because 1 kHz is reference frequency
and 0dB is a reference of the frequency weighting. When you perform calibration with the 250Hz calibrator,
select the frequency weighting of C or Z.
3．Spectrum display
Press the 'SPECT' button of CH1 in the DISPLAY section on the operation panel to display the spectrum.
4．Setting the frequency range
Use the up and down arrow buttons in the FREQ section of the operation panel to select the desired frequency
range as indicated in the upper right corner of the screen. You should first select a wider frequency range to
check the entire spectrum before selecting a suitable range.
The top buttons show the order with which the
buttons were pressed.

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5．Setting the voltage range
Use the up and down arrow buttons in the CH1 section on the operation panel to select a proper voltage range
in such a way that the 'RANGE OVER' lamp does not turn on and the green lamp is on. (If you consider about
the max. voltage output, it becomes 1 Vr range.)
6．Unit calibration
-1. Press the keys in the order [MAIN] > [INPUT] > [EU] > [CH1] to turn ON the [Y EU ON] to enable the unit
calibration function. (Default value of unit calibration value is 1.)
①②③④
-2. Press the keys in the order [MAIN] > [INPUT] > [EU] > [CH1] > [SP/EU] to open the SP/EU calibration
screen.
-3. Turn ON the ‘SEARCH’ button on the operation panel and adjust the search marker to the overall value
using the cross key. (See above figure)
-4. Press the keys in the order [MAIN] > [INPUT] > [EU] > [CH1] > [SP/EU] to open the [SET VALUE] setting
screen and input “94 (dB)” which is same as the displayed value on the sound level meter.
① ② ③ ④ ⑤

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The overall value of the calibration screen is changed into “94 dBEU”. Click [CLOSE] to close the
setting screen and return to the power spectrum measurement screen.
-5. Press the keys in the order [MAIN] > [INPUT] > [EU] > [CH1] to open the [Y EU NAME] and
input the arbitrary text, such as [spl (Sound Pressure Level)].
Click the [CLSE] button to close the setting screen. The display of [94 dBSPLr] and EU are
changed to SPL. (SPLr of r stands for effective value. When nothing is entered to the Y EU NAME,
r is not displayed. In this case, it displays 94 dB.)
-6. Adjust the search marker to the overall and check that the value is changed to [94dBSPLr] in the
measurement screen as well.
-7. Press the CAL button of the sound level meter to turn OFF the calibration signal and return to the
measurement state. Set the frequency weighting (A, C or FLAT) and time weighting (FAST) of the sound
level meter for analyzing. There is an analog signal which passes through the frequency weighting (A, C
or FLAT) depending on the type of sound level meter. Be careful with this matter.
-8. When changing the level range of the sound level meter while measuring
When the level range of the sound level meter is changed after the unit calibration, it is necessary to
change the range of the CF-7200 as well. For example, when the range is changed from 100 dB to 90 dB,
the AC out is amplified by +10 dB and outputted. Set the correction value in the following operation to
“-10dB”. Without this operation, 10dB larger than original value is displayed. It is necessary to perform this
correction operation or another unit calibration when you change the range of the sound level meter. If you
perform correction operation, please do not forget to return to the correction value to 0 dB for the next
measurement.
Press the key in the order [MAIN] > [INPUT] > [EU] > [CH1] to open the [dB CAL] setting screen. Select
[-10dB] from the pull-down menu and click [CLOSE] button to close the setting screen. -10 B correction
has been made to the displayed data.
Overall
① ② ③ ④

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-9. How to apply the A-weighting filter
It is possible to apply A-weighting filter to the CF-7200 side instead of applying it to the sound level meter.
There are two methods as follows. Please be careful not to apply frequency weighting to both sides of
sound level meter and CF-7200.
Operation 1: Applying A-weighting filter to the input signal (Analog filter)
The input signal isAD converted by passing through theA-weighting filter.
Press the keys in the order [MAIN] > [INPUT] > [INPUT COND] > [CH1] > [FILTER] and turn ON the [A
WEIGHT].
Operation 2: Applying A-weighting to the power spectrum (Digital filter)
Switching of the display which applies A/ C weighting or not applied any filter is possible in the power
spectrum.
Press the keys in the order [MAIN] > [ANALYSIS] > [FREQ CALC] > [WEIGHT] to turn ON the [A
WEIGHT]. This function is valid for the octave display in the following explanation.

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FrequencyA-weighting setting waveform
-10. Start the measurement with the ‘START’ button on the operation panel and stop the measurement with the
‘STOP’ button. Perform analysis in the arbitrary frequency range.
7．Measurement and averaging
The following description assumes that the measurement will be made using the power spectrum arithmetic
averaging function.
-1. Press the soft keys in the order [MAIN] > [ANALYSIS] > [AVERAGE] > [MODE], and set [PWR SP] to ON.
① ② ③ ④
-2. Press the keys in the order [MAIN] > [ANALYSIS] > [AVERAGE] > [TYPE], and set [NUM] to ON.
If the averaging is to be specified by the number of averaging times, press the [NUM] key. If it is to be
specified by the time, press the [TIME] key to set it on.
① ② ③ ④

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-3. Enter the number of averaging times in the "Average Number" dialog box, which is displayed when [NUM]
is set to ON after pressing the soft keys in the order [MAIN] > [ANALYSIS] > [AVERAGE] > [SET].
① ② ③ ④
-4. Turn on the 'AVG' button on the operation panel, and then press the 'START' button to start the
measurement.
When the specified number of averaging times has reached, the measurement will stop. When the lamp
on the 'AVG' button is on, it indicates that averaging is enabled. Press the 'STOP' button to interrupt the
measurement.
-5. Pressing the 'START' button will repeat the measurement.
Shows the progress of the averaging process

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8．Reading data
-1. Reading by searching
Press the 'SEARCH' button on the operation panel and use the right and left arrow buttons to move the
search point. The X and Y values of the search point will be displayed. The up and down arrow buttons
are used to more quickly move the search point.
-2. Peak list display
Press the soft keys in the order [MAIN] >[DISPLAY] >[LIST], and turn on the [ON] key. The set of spectrum
data will be presented in a list. Press the keys in the order [MAIN] >[DISPLAY] >[LIST] >[LIST TYPE], and
turn on [PEAK] to show the peak list.
① ② ③
① ② ③ ④
: Move slowly
: Move quickly

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9．Saving data
In principle, you can use a compact flash card (CF card) to save the data. You can save the data in the txt or
bitmap format and open the file on a PC and copy the data to a USB memory as appropriate. If your PC has a
CF card interface, you can also open the saved file directly from the CF card.
The data in the CF format (with the file extension of .dat) can be opened by other FFT analyzers, using the
DS-0221 FFT analysis software, for example.
The memory function of the model CF-7200 has been significantly improved. It is now compatible with the CF
(extension .dat), txt, and bitmap formats as well as voice memo and image snapshot functions. For details, refer
to the reference guide.
-1. After the measurement, display the data to be saved on the screen.
-2. Press the soft keys in the order [MAIN] > [MEMORY] > [UTILITY] >[SELECT MEDIA], and turn on the
[CARD] key.

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-3. Select the type of the data to be saved.
Press the keys in the order [MAIN] > [MEMORY] > [DATA] > [SAVE TYPE]. Then, turn on the [TEXT] and
[BMP] keys. By this, the data will be saved in the txt and bitmap formats, in addition to the CF format,
which is always used for the storage.
① ② ③ ④
-4. List display of the saved data
Press the keys in the order [MAIN] > [MEMORY] > [DATA]. Then, turn on the [LIST] key. This operation will
display the list of the data files saved.
① ② ③
-5. Click on the lowest unused number to move the selection cursor (the files will be saved to this location).
-6. Click the "Display Keyboard" button to open the keyboard, and enter a note after "Label:" as appropriate
(the label can be changed after saving the data).
-7. Click the 'SAVE' button to save the data.
-8. Click the [CLOSE] key to close the list window.
Saves the data in the bitmap format
Saves the data in the text format
"Display keyboard" button

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10. Reproducing data
-1. Press the keys in the order [MAIN] > [MEMORY]. [DATA]. Then, turn on the [LIST] key. This operation will
display the list of the data files saved.
① ② ③
-2. Click the data number of the data to be reproduced.
-3. Press the 'LOAD' button on the operation panel. The data will be reproduced on the screen.
11. Copying saved data to a USB memory device
When copying the data in the CF card to a USB memory device, the data can be copied either selectively or
entirely. Be sure to use a USB memory device type that has been verified for normal operation.
Manufacturer Model Capacity
Transcend TS1GJF110 1 GB
Sandisk SDCFH-2048-903 2 GB
Selection cursor
The line which displayed icon shows that there is a data. In this
example, the data is saved in both TXT and BITMAP formats. The data
always saved in CF format (.dat).

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-1. Insert the USB memory device. The USB icon will appear.
-2. Saving all data
①.Press the keys in the order [MAIN] > [MEMORY] > [UTILITY] > [COPY FILES] > [COPY FILES
TYPES]. Then, turn on [DATA].
②.In the confirmation dialog box that appears when the [CARD => USB] key is set to ON after pressing
the keys in the order [MAIN] > [MEMORY] > [UTILITY] > [COPY FILES], click [Yes] to start copying
the files.
The following message will be shown while the files are being copied. Clicking the 'CANCEL' button will
stop copying the data.
③.The following folders will be created in the USB memory device, and the data will be stored
in the "block" folder.
The USB icon will appear in the bottom
right of the screen.

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-3. Saving selected data sets
①.Press the keys in the order [MAIN] > [MEMORY] > [DATA]. Then, turn on the [COPY] key to show the
"Copy Data Memory" window, which is used to copy the memory data.
②.First, click to open the [Source] menu (CARD/INT/USB) on the "Copy Data Memory" window and
select "CARD" from the menu.
Then, click to open the [Target] menu (CARD/INT/USB) on the "Copy Data Memory" window and
select "USB" from the menu. Lastly, click the data list number (No.) for the data to be copied. To
cancel the selection, click again on the same number. You can select more than one data list
numbers.
① ② ③

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③.Click the [COPY EXECUTE] key to start copying the data.
-4. Removing the USB memory device
Press the keys in the order [MAIN] > [MEMORY] > [UTILITY]. Then, turn on the [REMOVE USB Memory]
key to disconnect the USB memory device and turn off the USB icon in the bottom right of the screen.
12. Dual window display
You can display both time waveforms and spectrum using two windows. Use either of the following two
methods for a dual window display:
Operation 1
Press the buttons in the order 'SPECT' > SELECT' > 'TIME'. Press the SPECT button of CH1 to show the
spectrum in one window. Further, press the SELECT button to divide the window into two sub-windows.
After that, press the TIME button of CH1 to display the time waveform. It results in the dual window of time
and spectrum. In this way, you can use two windows (channels) to measure the data.
Note that touching on the upper window area will make the upper window active. When any saved data is
reproduced, it will be displayed in the active window.
Operation 2
Press the soft keys in the order [MAIN] > [DISPLAY] > [FORMAT] > [TYPE]. Then, turn on [DUAL] to show
two windows. Make the upper window active and press the 'SPECT' button. Then, make the lower window
active and press the 'TIME' button to obtain the dual window display of spectrum and time waveform.
The USB icon disappears from the
bottom right of the screen.
① ② ③

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13. 1/3 octave display
Octave display function is to display the bundled to 1/3 octave or 1/1 octave data which is based on the power
spectrum. The displayed band (frequency band) is changed depending on the frequency range. Also, the
displayed highest and lowest bands are insufficient data, so they are for reference.
-1 Press [SELECT] button to activate the lower screen (Check the indication of the SELECT button.) or touch
the lower screen of the data area.
-2 Press keys in the order [MAIN] > [ANALYSIS] > [DATA TYPE] > [FREQUENCY] > [PWS] > [OCTAVE] > [1/1]
or [1/3] to turn ON [1/3].
① ② ③ ④

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The following figure shows the 1/3 octave display in the lower screen and power spectrum in the upper screen.
-3 Saving the octave display data
Please refer to the “9. Saving data”. When the octave data is saved, an extension of “.dat” is saved the original
data of power spectrum. “.txt” is saved octave data, but octave data cannot save as “.dat” data.
-4 How to cancel the octave display
After activating the octave screen by the [SELECT] button (with the indication of SELECT button), press
[SPECT] button of CH1, and turn off the indication of the SELECT button.
14. Arbitrary setting of Y-axis scale
The following description assumes that the upper limit as 70dB and lower limit as 20dB.
Press the keys in the order [MAIN] > [DISPLAY] > [X Y SCALE] > [Y-AXIS] > [MANUAL] > [UP SCALE] / [LOW
SCALE] to input upper limit value to 70 and lower limit value to 20.

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15. 3D display
-1. Display the power spectrum or 1/3 octave by referring the operation procedure 12.
-2. Turn OFF the green light of the ‘AVG’ button of the operation panel to cancel the averaging function. When
the ‘AVG’ is turned ON, the averaged data is 3D displayed.
-3. Stop the measurement by pressing the ‘STOP’ button on the operation panel.
-4. Press the keys in the order [MAIN] > [DISPLAY] > [3D] > [ON] to turn ON the 3D display.
-5. Turn ON the ‘START’ button on the operation panel and start measurement. The data is displayed in 3D.
-6. The display method can be changed according to your requirement.
Press the keys in the order [MAIN] > [DISPLAY] > [3D] > [SET 3D COND] to select the display method with
[COLOR] and [DRAW].
Example 1: Display of ‘COLOR’ OFF, and ‘DRAW’ OFF

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Example 2: Display of ‘COLOR’ OFF, and ‘DRAW’ ON
Example 3: Display of ‘COLOR’ ON (Both ‘DRAW’ ON/OFF are the same)
When the 3D data area is touched, the cross section of X and Y is displayed.
-7. Changing number of drawings
Press the keys in the order [MAIN] > [DISPLAY] > [3D] > [SET 3D COND] > [LINE NUM] to set the arbitrary line
number (10 to 400).
Cross section Y
Cross section X
3D + Trace data display switch key
3D + Data display switch key
Only 3D display switch key
3D + Data + Trace display switch key