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Scarlet Tech ST-25D User Manual

Sound level meter
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ST-25D
ST-25D
Sound Level Meter
User Guide

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Summary of Contents for Scarlet Tech ST-25D

  • Page 1 ST-25D ST-25D Sound Level Meter User Guide...
  • Page 2 Precaution * Use the sound level meter gently, especially for microphone part, microphone is delicate sensor that require careful handling, please avoid any crashing, knocking and hitting, no water or oil entering. * If choose to use alkaline batteries, please use high capacity of alkaline batteries. And remember to remove the batteries when don’t use sound level meter for more than one week.

  • Page 3: Table Of Contents

    Contents 1. General Introduction 2. Specification 3. Structure Features and Function 4. Preparation 4.1 Preparation before using 4.2 Use of windscreen 4.3 External power supply 4.4 Check and change battery 5. Calibration 5.1 Sound calibration Interface 5.2 Use ST-120 to calibrate 5.3 Directly input sensitivity level 5.4 Calibration record 6.

  • Page 4: General Introduction

    The design of low power dissipation and the automatic switchover of battery and the external power can support the instrument to work for a long time. With embedded 32 MB flash memory turns ST-25D a reliable data logger. It also has a pre-installed 32GB SD card for WAV recording function.

  • Page 5: Specification

    Specification Model ST-25D Fulfils Standard IEC 61672 Class 2 / IEC 61260 Class 2 / IEC61252:2002 Normal Frequency 20 Hz ~ 12.5kHz ± 1 dB (not including microphone) Measurement Range 28dB-133dB (145dB Peak) Z(FLAT): 38 ~ 130dB / C peak: 145dB / Z(FLAT): peak: 145dB Measurement Level 0.1dB...

  • Page 6: Structure Features And Function

    Structure Features and Function The outline of the Sound Level Meter is shown in Figure 1. It consists of microphone, preamplifier and the main unit. During normal operation, the measuring microphone and the preamplifier are installed on the head of the main unit, connected with the main unit through knurled nut.
  • Page 7 Microphone Windscreen anti-drop hook Preamplifier Knurled nut Windscreen Security slot Display SD card indicator Keypad GPS antenna port SD card slot (pre-installed a 32GB SD card) ST-25D Mini USB port AC output Battery indicator GPS indicator Status indicator RS 232...
  • Page 8 Fig 2 Preamplifier-Main device connector (X9 socket) Definition Power supply Not connected Signal input Not connected Signal ground Not connected Fig 3 AC output (3.5mm phone jack/stereo socket) AC output signal’s amplitude won't exceed 1V. Its relationship with input signal is shown in the table below: AC output input signal minus 10dB...
  • Page 9 Fig 5 RS232 port Definition Power Online Ground DC Output Not connected Not connected Not connected Fig 6 LED indicators GPS status Working status indicator indicator Working status indicator Status LED behavior Measurement starts Flashes Measurement paused Static On Measurement Stopped GPS status indicator Status LED behavior...
  • Page 10 Fig 7 Keypad Down Left Right Cancel Enter Delete Setup On / Reset Backlight Start / Pause ST-25D Output Icon Name Function On/Reset Power on; Restart the instrument Cancel Return to previous menu from the current menu Left Move the cursor to left...
  • Page 11 Fig 8 Status bar & icon definition Remark Displayed content Meaning Statistics Analysis mode Integral Analysis mode GPS (Optional) GPS positioning measurement The bars from the left: Statistics, Integral The number of working analyzers Color: white means open, red means startup Statistics &...

  • Page 12: Preparation

    Preparation 4.1 Preparation before using ① Check whether the microphone has been installed correctly. ② Check whether battery has been put in. ③ If necessary, calibrate it with a sound calibrator. Regular method is in chapter 5. ④ The meter should be tested by relevant department regularly (such as one year), so as to ensure its accuracy.

  • Page 13: Calibration

    Calibration There are two interfaces: calibrate and record. The instrument can save sound calibra- tion record of 256 groups. 5.1 Sound calibration Interface When the user enters the "Calibrate" submenu from main menu, shown below: "Condition": the temperature of the environment. "Mic.

  • Page 14: Use St-120 To Calibrate

    In the current mode, the cursor can only be moved on "dBA" at the right side of "Current SPL" and "Calib.". If the user wants to modify the parameters, they should press Key, shown below: The status changing from "Ready" to "Modify" allows the user to modify "Free field", "Calibrator SPL", and "New Sensiti."...

  • Page 15: Directly Input Sensitivity Level

    Insert the ½ inch microphone to the hole of ST-120 sound calibrator, turn on the power supply. Press key. The meter automatically starts calibration. The sound pressure level is displayed after "Current SPL". This sound pressure level is approximately equal to the calibrator’s sound pressure level minus free field correction.

  • Page 16: Calibration Record

    5.4 Calibration record When the cursor is moved to the "Calibrate" and press the key to enter the Calibration record interface, shown below: The interface displays the calibration message of current serial number, move the cursor to the "No", and press key to view the calibration message of the other serial number.

  • Page 17: Operation

    Operation There are four display interfaces in the main menu interface: measurement interface, setup interface, recall interface and calibration interface. 6.1 Main menu When the user presses key for above 2s and then releases it, the meter goes to the main menu: In the main menu, there are four submenus: Measurement, Setup, Recall, and Calibrate.
  • Page 18 Note: The green options mean the menu status can be changed by keys. The blue background frame at the first line respectively displays from left to right: current analyzer mode, work status, calendar clock and power indication. When the cursor is moved to the option of "Statistics", the user can use key to change the menu options.
  • Page 19 6.2.1.1 Once measurement interface In the noise measurement interface, when the menu in the measurement mode displays “Once”, the meter goes to “Once” measurement mode. In the “Once” measure- ment interface, there are two display modes: List and Fig. interface. 6.2.1.1.1 List measurement interface The list interface has two pages: List1 and List2.
  • Page 20 1) Statistic distribution graph Note: The green options mean the menu status can be changed through cursor and parameters key. In the middle is “Sta. Figure”, the y-ordinate is percentage, and the x-ordinate has 140 points, every point represents 1dB. When the cursor is moved to “94dB”, the user can view the percentage that every sound pressure level takes up by pressing the key.
  • Page 21 6.2.1.1.3 Extra interface The option of extra Ln is open in the analyzer setup, the measurement interface of STA will add an interface named EXTRA, shown below 6.2.1.2 24H automatic measurement interface 24H measurement means that the measurement automatically starts every one hour at integral o’clock, totally 24 times.
  • Page 22 There are six measurement indexes: Linst, Leq,T, Lmax, Ld, Ln, Ldn in the current frequency weighting and time weighting. The bottom line "Start@2015-02-10 13:47:30" in the black background is the first time of starting the measurement. "H01" is the first time section.
  • Page 23 The Fig. display interface can display 24h sound pressure level chart. The y-coordinate is sound pressure level and the x-coordinate is hour, totally 24 columns. “Leq,T” means that the currently displayed index is Leq,T. When the cursor is moved to this place, press keys to change it to Lmax, Lmin, L5, L10, L50, L90, and L95 etc.
  • Page 24 6.2.2.2 24H automatic monitoring According to the specific requirements, after checking and adjusting the clock, set the time and run mode, frequency weighting and time weighting used in statistics and group name etc. In the measurement menu, when the cursor is moved to the bottom line in blue background, change the second menu option to “24H”...
  • Page 25 6.2.3.1 Sim. interface From the third to the eighth line are measurement content which is concerned about frequency weighting in the current measurement interface, and the details are shown below: Wei (frequency weighting) Measurement indexes LAFp，LAFmax，LAFmin，LAeq,T，LApeak，LAE LCFp，LCFmax，LCFmin，LCeq,T，LCpeak，LCE LZFp，LZFmax，LZFmin，LZeq,T，LZpeak，LZE 6.2.3.2 List interface Move the cursor to the "Sim.", press the key to enter the "List"...
  • Page 26 “Wei: A&C” is the frequency weighting in the current measurement interface which shows the indexes of A and C weighting. When the cursor is on “Wei”, the user can choose two weightings of A, C and Z by pressing keys, and the measurement content will change in response.
  • Page 27 6.2.3.4 Huge interface When the cursor is on “List3”, the user can enter “Fig.” display interface by pressing keys, shown below: The big characters and dial figure in the middle black background are the measurement result of index “LAFp” at the second line, and the data is changing with the environment every 0.5s.

  • Page 28: Setup

    Setup The second line is the version of software and hardware; the middle is the two setup options with icon. The user moves the cursor to any option and press key, then will go into the setup interface of the option. Below the icon options are the options of time and language, the cursor can stay at the year, month, day, hour, minute and second option, the user can setup the calendar clock by pressing...

  • Page 29: Rtc

    7.1 RTC RTC option: the cursor can be moved among year, month, day, hour, minute and second. Press key to set the RTC. The bottom line shows the message of battery voltage. "Vusb" is the voltage of USB socket, "Vcc" is the voltage of battery, "Vbat" is the voltage of backup battery socket. When GPS is authorized, it's recommended to use the GPS to calibrate the RTC, and it's with higher precision.
  • Page 30 When the measurement is started, once getting the time, the instrument will finish the measurement and save the measurement result. In the analyzer setup interface, "Ts" in every module can be set independently. 7.2.2 Run mode setup "Run mode": the trigger source to startup, there are four modes that can be chosen: Key, Time, Limit and Interval.
  • Page 31 c) Limit When the mode of "Limit" is chosen, shown below: "Limit": When the value exceeds the setting limit, the instrument will be started. The value can be chosen from 0 to 180. When the cursor is moved to "Run mode", the user can enter setup interface of Interval run mode by pressing key.
  • Page 32 Analysis mode: Total value Time weighting: F, S and I can be chosen. Frequency weighting: A, C and Z can be chosen. b) Integral analyzer Only Ts and Run mode are adjustable.

  • Page 33: Basic Setup Interface

    7.3 Basic setup interface There are three pages in the basic setup interface: "Basic Setup1", "Basic Setup2" and "Basic Setup3". In the Setup interface, move the cursor to "Basic" and enter the "Basic Setup1" inter- face, and press key to switch. There are five analyzer setup options from up to down respectively: "Multi-analyzer", "Name Setup", "Hardware Setup", "Auto power"...
  • Page 34 7.3.1 Multi-analyzer Setup "sync": Press key, each analyzer will start measurement at the same time. Press key to change "sync" to "async", and press key, the instrument will only start the analyzer at the current measurement interface. "Ts": Ts is the measurement time, the setup method is seen in Chapter 7.2.1. "Run mode": the trigger source to startup, see details in Chapter 7.2.2.
  • Page 35 7.3.3 Hardware setup "Backlit" can be set as "Open" constantly or selected within 10s-900s with 10s inter- vals. When the user doesn’t press any keys in the specified time, the Backlight is automatically turned off. "Bright": default value is 25 which can be chosen between 4 and 49. When the value is greater, the backlight is brighter.
  • Page 36 "Output": the type of output signal on AC output interface which can be chosen among N/A, AC and 1 kHz. If 1 kHz is chosen, the meter’s self-noise is increased by 3-5 dB. The 1 kHz Output signal will be closed when the measurement is in Oct analysis mode. And the "N/A"...
  • Page 37 7.3.4 Auto Power Setup "Auto Power": "Yes" and "N/A" can be chosen. When "Yes" is chosen, the instrument can open and off at the specified time shown below. "Auto Power On": the form is "day, hour, minute and second". "Auto Power Off": the form is "day, hour, minute and second". When one of the options is adjusted to end, there will display "**", which means this option won’t take part in the compare.
  • Page 38 When the status bar at the right corner shows "R:-13", the remaining time for voice note is 13s. Note: the WAV file for voice note has precision of 8k Hz sampling, so it's only recom- mended for subject listening. 7.3.6 Record Setup "New file/Same file": "New file"...
  • Page 39 7.3.7 Bluetooth (Optional) "Power": Master, Slave and off. Press key to open the slave mode and press to open the master mode. The master mode can also be connected to the Bluetooth printer to print the measurement result. When the mode is set successfully, the left corner will prompt the master or slave mode is setting.
  • Page 40 7.3.8 RS232 setup "Baud rate": 4800, 9600 and 115200. "FlowCont.": When the control flow is yes, then the instrument will check the voltage of pin DB9-7 before transmitting data to RS232. And low voltage means the outer device is busy and the instrument won’t send data to RS232. 7.3.9 Default "1.

  • Page 41: Data Recall

    Data Recall ST-25D Sound level meter has 32MB flash memory which assures reliable data storage, and the data stored in the instrument can be transferred to the computer by RS-232, USB, or printed out by mini-printer. Also, a pre-installed 32 SD card enables ST-25D large capacity storage and WAV recording function.

  • Page 42: Once Measurement Result

    8.1 Once measurement result recall When the recalled data is the result measured in the one measurement method, the method displays “STA.-One”. Press key to go into the list interface, and press again to enter the Fig. interface, shown below: The list interface shows the information of measurement name, date, start time, measurement method, analyzer mode, instrument model, series, calibration date and sensitivity level etc.

  • Page 43: Automatic Monitoring Result Recallrecall

    In the sta. Figure and Acc. Figure display interface, the user can move the cursor to the middle “dB” under the graph, press key to view the statistic percentage and accumulative percentage of different sound pressure level. If the extra Ln is open in the analyzer setup interface of STA, the measurement data will add L1, L99 and 5 user-defined Ln, shown below: 8.2 24H automatic monitoring result recall When the measurement result is monitored automatically in 24 hours, the method...
  • Page 44 Press key in the interface to display the graph of Leq-T, shown below: In this interface, when the cursor is moved to “Leq_T”, by pressing key, the user can view Lmax, L5, L10, L50, L90, L95-T chart. key can move the cursor. When the cursor is on “21:”, the user can view the data of each period via key.

  • Page 45: Integral Measurement Result Recall

    8.3 Integral measurement result recall When the recalled data is the result measured in the integral measurement method, the method displays “OVERALL-INT”. Press key to go into the list interface, shown below:...

  • Page 46: Delete Data

    8.4 Delete data In the data recall interface, the user can choose to delete several groups of data or delete all data. 8.4.1 Delete all data In the data recall interface, whatever the number is the cursor at, as long as you press key, there will a notice on the screen: “Clear all data?”, shown below: Press key to delete all data, and press the other keys to return the recall interface.

  • Page 47: Change To U-Disk Mode And Recall

    8.4.3 Delete multi-group of data In the data recall interface, press key to choose the number, then the background color of this number will be blue. If the user presses key again, the number won’t be chosen. The user can choose more than one group once, and press key, then there is a notice: “Do you sure to delete the chosen data?”...

  • Page 48: File Format Description

    8.6 File Format Description The sound level meter is using FAT table for file management, and supports FAT16, FAT32 format, when formatting the SD card, it will turn to default FAT32 format. All saved measurement result files are saved in a folder, user can name the folder. Measurement results are saved in a file with the extension name “AWA”.

  • Page 49: Gps Positioning Measurement

    GPS positioning measurement (Optional) When the instrument has GPS module, it can be used for positioning measurement and calibrating the RTC which is with higher precision. Firstly, connect to the external antenna, and put the antenna outside the room where the antenna can directly receive the satellite signal.

  • Page 50: Distance Measurement

    9.1 Distance measurement When the antenna is connected to the satellite, the message of GPS time, the current position (starting point) and the working satellites. In this interface, press key to show the position message of finishing point and the displacement and velocity of the starting point.

  • Page 51: Gps Positioning Measurement

    9.3 GPS positioning measurement In the noise measuring interface, move the cursor to the "Statistics" and press key to enter the GPS interface. Open the GPS module and startup it, the position message of the starting point will be shown in the interface. The message of GPS refreshes every second.

  • Page 52: Data Export

    Data Export ScarletSound for Scarlet Tech Sound Level Meter delivers easy-to-use, intuitive data monitoring and management with Windows based PC. Software download and installation 1. Connect the USB drive comes with the package to your PC to find ScarletSound installer.
  • Page 53 Settings The data stored in the sound level meter of ST-25D can be transmitted to the computer by RS232 and USB. Connect the device to the PC by RS-232 or USB cable, and then run the ScarletSound Application. Click Setup to go to Setup menu.
  • Page 54 Recall the data Select desired file named “dd-mm-yyyy hh:mm:ss”, the distribution graph and the data will be displayed in the right side. 10.5 Save the data to PC Save the data as the format of .xls by ScarletSound by clicking “Export”. Read data from files Click “Import”...
  • Page 55 Calibration record Read the calibration record Go to Calibration page, click the option of "Read" to download the calibration record from the instrument, and the data will be shown in the interface of the software. Save the calibration record to PC Click “Export”...
  • Page 56 Note: The USB port communication method don't support for reading the basic infor- mation Online Monitoring The instantaneous SPL and 0.5s displayed SPL can be monitored. Firstly, set the interval of logging in analyzer setup 2 to at least 100ms. And enter the measurement interface, make sure the corresponding analyzer is open.

  • Page 57: Overload Indication

    Overload indication When the noise to be measured exceeds for sound level above the upper limit of meter’s measurement range, the meter may display "Overload" on the top. The overload indication is presented as long as the overload condition exists or 1s. In the statistical analysis process, if overload appears, the overload indication will latch until the measurement results are reset or next time measurement are started.

  • Page 58: Annex

    Annex Annex 1 Response characteristics Annex 1-1 Directional response Frequency (dB) 15° 30° 45° 60° 75° 90° 105° 120° 135° 150° 165° 180° (Hz) 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 10000 12500 10.0 10.0 14.3 16000 11.1 13.4 12.8...
  • Page 59 Z weighting response when directivity is 90 degree: Z weighting response when microphone type is random:...

  • Page 60: Gps Overview

    GPS positioning measurement of ST-25D mainly measures longitude, latitude, altitude, movement speed, movement direction and straight-line distance between two points. The unit of longitude and latitude is degree. The user can find the satellite pictures of relevant longitude and latitude through inputting the following content on the internet.

  • Page 61: Filter Attenuation Characteristics

    Annex 3 Filter attenuation characteristics Relative attenuation of 1/3 octave band pass filter at 12.5kHz center frequency Z weighting response when microphone type is random:...

  • Page 62: Safety, Handling, & Maintenance

    Safety, Handling, & Maintenance Important safety information WARNING: Failure to follow these safety instructions could result in re, electric shock, or other injuries, or damage to sound level meter or other property. Read all the safety information below before using sound level meter.
  • Page 63 Scarlet Tech Co., Ltd. © 2015 Scarlet Tech Co., Ltd. All rights reserved. 4F-3, No. 347 , HePing E Rd, 2nd Sec, DaAn District, Taipei City 106, Taiwan info@scarlet.com.tw www.scarlet-tech.com version 220309...

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