User's Manual Datalogging Sound Level Meter Model 407764 • Range: 30dB to 130dB • 4-digit LCD Display with 0.1dB resolution • A and C Frequency Weighting • RS-232 PC Interface with 128,000 point datalogger and Date / Time Stamp • Auto-Ranging Introduction Congratulations on your purchase of Extech’s Datalogging Sound Level Meter. The meter is capable of performing all your noise measurements needs in addition to it’s capabilities for data acquisition (direct data storage to a PC) or datalogging (data storage to internal memory for later download). Data storage enables the user to save data, analyze data and generate reports. This professional meter, with proper care, will provide years of safe reliable service. Specifications Applicable Standards Accuracy Frequency range Measuring level Frequency weighting Microphone Display Bargraph Sampling rate Memory size Datalogging sample rate Time weighting MAX Level ranges Auto range Linearity range Alarm function AC output DC output Power supply Battery life AC adapter Operating temperature Operating humidity Storage temperature Storage humidity Memory size RS-232 Interface Dimensions Weight Accessories IEC651 Type 2, ANSI S1.4 Type 2 ±1.5dB (under reference conditions) 31.5Hz - 8KHz 30 - 130dB A and C 0.5” Electret condenser microphone 4-digit LCD Resolution: 0.1dB Display period: 0.5 sec. 50dB scale (1dB steps). Display period: 50mS; Auto-ranging: 100dB scale, 2dB steps 50mS 128,000 records / 255 sets (non-volatile memory) 1 to 86,400 seconds per record FAST: 125mS, SLOW: 1 sec. Maximum reading held 30-80dB, 40-90dB, 50-100dB, 60-110 dB, 70-120dB, 80-130dB (Total of 6 ranges) 30 to 130dB 50dB OVER indicator for readings higher than high limit. UNDER indicator for readings lower than low limit. 0.707 Vrms at Full Scale Output impedance approx. 600Ω 10mV / dB Output impedance approx. 100Ω Four 1.5V ‘AA’ batteries Approx. 30 hrs continuous operation Voltage: 6VDC Voltage Ripple: < 100mVpp Supply Current: > 100mADC Socket: Pin Ground Casing: Positive External Diameter: 3.5mm o o 32 to 104 F (0 to 40 C) 10 to 80%RH o o 14 to 140 F (-10 to 60 C) 10 to 80%RH 128,000 data records with Date and Time Stamping Baud rate: 9600bps 10.4 x 2.8 x 1.4” (265 × 72 × 35mm Approx. 11.5 oz. (358g) including battery Batteries, carrying case, screwdriver, windscreen, 3.5mm plug, RS-232 TM cable , Windows compatible software. Safety symbols Meter is protected throughout by double insulation or reinforced insulation. CE Complies with EMC 2 Model 407764 Version 2.1 9/07 Meter Description 1. Microphone 2. Display 3. Power switch 4. Level range control switch 5. MAX hold switch 6. Frequency weighting switch 7. Response time select switch 8. AC output terminal 9. DC output terminal 10. CAL (calibration) pot. 11. External DC 6V power 12. RS-232 interface connector 13. Battery cover 14. Tripod mounting screw 15. Wind-screen (Figure 1) Display Description 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Range selection Date information SPL: Instantaneous sound pressure level Low-Battery MAX: Maximum SPL value is held Data recording Measurement value Memory full Units Frequency weighting (A/C) TIME function 50dB level (Bargraph) Over range SLOW time response FAST time response Under range (Figure 2) 3 Model 407764 Version 2.1 9/07 Measurement Preparation • Read the following safety information before attempting to operate the meter • Use the meter only as specified or the meter's built-in protection may be impaired. Maintenance & Cleaning • Service not covered in this manual should be performed by qualified personnel • Periodically wipe the case with a dry cloth. Do not use abrasives or solvents. Battery Replacement symbol appears on the LCD. Replace When the battery voltage drops to a critical level, the batteries as soon as possible after the battery symbol appears. The batteries (4 AA) are located in the rear battery compartment. Remove the single Philips head screw (center rear) for access to the batteries. Measurements Default Configuration 1. The meter's default configuration is as follows: 40 to 90dB, 'A' Frequency Weighting, and 'FAST' Response Time 2. The LCD will reflect the meter's configuration. Measurement Considerations 1. Use a windscreen to cover the microphone in windy conditions. 2. Calibrate the meter often, especially if the meter has not been used for a long time. 3. Do not store/operate the meter in high temperature/humidity for long periods of time. 4. Keep the meter and the microphone dry. 5. Avoid severe vibration when using the meter. 6. Remove the battery when the meter will be stored for long periods of time. Frequency Weighting Change the Frequency Weighting by pressing the 'A/C' button. The 'A' or 'C' icon will display on the right-hand area of the LCD. Note: With ‘A’ weighting selected, the meter responds like the human ear (boosting and cutting the noise amplitude over the frequency spectrum - see Appendix). ‘A’ weighting is used for environmental measurements, OSHA regulatory testing, law enforcement, and workplace design. Select ‘C’ weighting for flat response measurements (no boost or cut). ‘C’ weighting is suitable for the sound level analysis of machines, engines, etc. Most OSHA related testing is performed using 'A' Weighting and SLOW Response Time settings. Response Time Change the Response Time by pressing the 'FAST/SLOW' button. The 'FAST' or 'SLOW' icon will display on the upper area of the LCD. Note: Select FAST to capture noise peaks and noises that occur very quickly. In FAST mode, the meter responds in 200ms. Select the SLOW Mode (meter responds in 500ms) to monitor a sound source that has a reasonably consistent noise level or to average quickly changing levels. Selection of Fast or Slow is determined by the application and any directives or standards related to that application. Auto/Manual Range Press the LEVEL button up arrow to scroll through the following ranges: 30-80dB, 40-90, 50-100dB, 60-110, 70-120, 80-130 and 30-130dB (auto). The display will reflect the range for each button press. Notes: Use Auto Range when the noise source is relatively steady. Use one of the Manual ranges may be required if the dB levels are changing over a wide range. 4 Model 407764 Version 2.1 9/07 Operation 1. 2. 3. 4. Power the meter and select the desired Response Time (Fast or Slow) and Frequency Weighting (A or C). Select the desired range. Hold the instrument comfortably in hand or position on tripod. Point the microphone toward the noise source, the sound pressure level will be displayed on the meter’s LCD display. When MAX (maximum hold) mode is selected by pressing the MAX key, the instrument captures and holds the maximum noise level reading on the display. Press the MAX key again to clear the MAX reading. Calibration Note that a Sound Level Calibrator is required. Set up the meter as listed in Step 1 below. To calibrate the meter; 1. 2. 3. 4. Display: SPL (dBA) Response Time: FAST Disable the MAX function Range: 70 to 120dB. Insert the microphone carefully into the sound level calibrator. Power the calibrator and adjust the Sound Level Meter’s CAL potentiometer (as shown in figure at right) to match the Calibrator’s output. Typically, a Sound Level Calibrator will supply 94dB or 114dB at 1KHz. Adjust the Sound Level Meter’s CAL potentiometer for a 94dB or 114dB LCD display (Figure-3) Analog output The 407764 has two analog output jacks located on its right side; one for AC and one for DC. For DC, the meter transmits 10mv / dB. For AC the full scale value is 0.707V. The output impedance is 600Ω for AC and 100Ω for DC. The supplied 3.5mm stereo mini-plug can be used to assemble a cable to connect to either of the meter’s analog output jacks. When using a stereo plug, like the one supplied, short the Tip and the Ring (see diagram below). Ground (negative) connects to the Sleeve while the positive signal is taken from the Tip/Ring. For mono plugs, ground connects to the Sleeve while the positive signal is taken from the Tip. The meter output can then be transmitted to a chart recorder, datalogger, or other data storage device. (Figure 4) Sleeve Tip Sleeve Tip Mono Stereo Ring 5 Model 407764 Version 2.1 9/07 DataLogging The internal memory of the meter can store up to 128,000 reading in up to 255 recording sessions (called sets). Prior to beginning data storage, the meter’s real time clock and the datalogger’s sample rate must be set using the supplied software. The clock is set in the Control Panel window and the sample rate is set in the Logger window. 1. Set the real time clock (if required). 2. Set the sample rate (if required). 3. To record data, press & hold the RECORD key for 3 seconds until the “RECORD” symbol flashes once per second on the LCD. Press the Record key again to stop recording data. 4. If the recording memory is full, the “FULL” symbol will appear on the LCD. 5. To clear the recording memory press and hold the RESET key and power the meter. The LCD will show the “dEL” icon letting the user know that the datalog memory has been cleared. 6. To Download or Record data via a PC refer to the PC Interface section below. PC Interface Connecting the Meter to a PC Refer to Figure 5. Connect the 9-pin male connector to the Sound Level Meter, and connect the 9-pin female connector to the 9-pin COM1 PC port. PC Requirements (figure 5) • 486 IBM compatible PC or better • One 3.5" high density disk drive • Available serial port. • 4M Bytes H.D. storage space • EGA or VGA monitor • Windows 95, 98, 2000, NT, XP Operating System • 3-button or 2-button Microsoft compatible mouse. At least a 486 PC is recommended for displaying all software windows with a fast sampling rate (such as 1 second). If a 386/25 PC is used, you can only open one window (LIST, GRAPH, ANALOG) at a time when using fast sampling rates. Installing the Windows Application Program Follow the instructions on the disk for installation. When installing the software, please use the Visual Basic version (VB) on installation CD. 6 Model 407764 Version 2.1 9/07 Software Control Panel Description The Control Panel (Figure 6) METER SIMULATION The left side of the Control Panel window provides a replica of the meter’s front panel and display. MAX: Hold and update maximum value A/C A/C weighting selection RESET Reboot and clear the data memory F/S Fast/Slow selection REC Enable datalogging LEVEL Set range DATA ACQUISITION CONTROLS and DISPLAYS MIN: MAX: TIME: SAMPLING TIME PC SAMPLING: <--RESET-->: SYSTEM TIME SET: SAVE AS: OPEN FILE: FILE NAME: START RECORDING: STOP RECORDING: EXIT Displays the minimum value recorded Displays the maximum value recorded Displays the Real Time Clock Setting Display of data acquisition sampling rate (Fig 7) Opens data acquisition sampling rate selection box. (Datalogging sample rate is set in the MEMORY “Logger” window) Resets the MIN and MAX stored readings Sets the meter’s clock to the value of the pc clock Opens the data file storage window (*.dat) Opens the data file retrieve window (*.dat) (Fig.8) Displays name and location of data acquisition file After opening a file, click to start recording. Stop recording and close the file Close program (Figure-7) Selecting the datalog sample rate (Figure-8) Opening a datalog file (*.dat) 7 Model 407764 Version 2.1 9/07 DISPLAY SELECTIONS (Figure-9) GRAPH (Figure-10) LIST (Figure 11) ANALOG Logger Window (memory setup/ data download) The Logger window sets the sample rate of the meter’s internal memory and provides the controls to download display and save stored data. MEMORY Displays memory size REMAINING Displays amount of unused memory TIME OF METER When clicked, downloads and displays the meter’s date and time ID CODE Numeric Identification code. Enter the code in the box and click on the bar to store the code. SAMPLING Datalogger sample rate. Enter the sample rate in the box (in seconds) and click on the SAMPLING bar to store the value. NUMBER OF SETS Click on the bar to download the stored data TIME OF RECORDING Click on the bar to display sets downloaded. Click on a set to select data for display NUMBERS OF REC Displays the number of records (data points) in the selected set. SHOW DATA Display, Save or Graph data from selected set 8 Model 407764 Version 2.1 9/07 DATA DOWNLOAD PROCEDURE 1. Click the MEMORY icon in the Control Panel screen. 2. Click the NUMBERS OF SETS button, the number of sets will appear. 3. Click on the TIME OF RECORDING button to view each recorded set. 4. Click on a SET in the TIME OF RECORDING box. The number of records in the set will appear and the data will be downloaded from meter to PC. Save to disk if desired. 5. Click the SHOW DATA button for details on each record. Figure 13 shows the data list. Select SAVE, PRINT, GRAPH, or EXIT from the menu choices. Note: In the example for Figure 12, there are 3 sets of recorded data in memory. Set No. 3 has 15 records. Note: If you need to change the ID CODE or the SAMPLING time, click on the desired parameter, type the changes and click on the bar. (Figure-13) – List of datalogged set (Figure-14) – Graph of datalogged set (Figure-15) – Selecting a range of datalogged records 9 Model 407764 Version 2.1 9/07 Calibration / Repair Services Extech offers complete repair and calibration services for all of the products we sell. For periodic calibration, NIST certification or repair of any Extech product, call customer service for details on services available. Extech recommends that calibration be performed on an annual basis to insure calibration integrity. Warranty EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of defects in parts and workmanship for one year from date of shipment (a six month limited warranty applies on sensors and cables). If it should become necessary to return the instrument for service during or beyond the warranty period, contact the Customer Service Department at (781) 890-7440 ext. 210 for authorization or visit our website at www.extech.com (click on Contact Extech and go to Service Department to request an RA number). A Return Authorization (RA) number must be issued before any product is returned to Extech. The sender is responsible for shipping charges, freight, insurance and proper packaging to prevent damage in transit. This warranty does not apply to defects resulting from action of the user such as misuse, improper wiring, operation outside of specification, improper maintenance or repair, or unauthorized modification. Extech specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable for any direct, indirect, incidental or consequential damages. Extech's total liability is limited to repair or replacement of the product. The warranty set forth above is inclusive and no other warranty, whether written or oral, is expressed or implied. Support line (781) 890-7440 Technical support: Extension 200; E-mail: [email protected] Repair & Returns: Extension 210; E-mail: [email protected] Product specifications subject to change without notice For the latest version of this User’s Guide, Software updates, and other up-to-the-minute product information, visit our website: www.extech.com Extech Instruments Corporation, 285 Bear Hill Rd., Waltham, MA 02451 Copyright © 2005 Extech Instruments Corporation. All rights reserved including the right of reproduction in whole or in part in any form. 10 Model 407764 Version 2.1 9/07 Appendix - Typical ‘A’ Weighted Sound Levels 140 50 HP Siren (100') 130 120 Jet take-off (200') Riveting machine 110 100 90 Subway (20') Chain saw Boiler room 80 Freight train (100') Pneumatic drill (50') 70 Speech (1') Vacuum cleaner (10') 60 Large Office Large store 50 Residence Small office 40 Residential area (night) 30 20 Sound studio Whisper (5') 10 Threshold of hearing 0 11 Model 407764 Version 2.1 9/07 Software Protocol Data Protocol Baud rate: 9600bps Byte1 Byte2 Byte3 Byte4 Byte5 02 Status Function 03 Leading byte Ending byte Status Byte2 Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 0 Fast C Normal Normal Normal 0 0 0 30-80 1 Slow A Max Full Rec 0 0 1 40-90 0 1 0 50-100 0 1 1 60-110 1 0 0 70-120 1 0 1 80-130 1 1 0 30-130 1 1 1 Function Byte3 2 Bit7 Bit6 Bit5 Bit4 (x10 ) Bit3-0 (x10) 0 Normal Normal Normal 00-19 1 OVER UNDER BT Function Byte4 0 -1 Bit7-4 (x 10 ) Bit3-0 (x10 ) 0 00-99 1 Command Protocol Set time and date - Send 7 bytes D YY MM dd hh mm ss leading byte year month date hour min sec Set sampling rate – Send 3 bytes W high byte low byte leading byte 1 – 65535 sec Set ID code – Send 3 bytes X high byte low byte leading byte 1 – 65535 Get software version – Output “V” - Receive 1 byte (0 – 255) Get system argument – Output “Y” – Receive 10 bytes ID Code Version ID code Data sets Last address Sample rate 2bytes 1 byte 1 byte 1 byte 3 bytes 2 bytes Get time and date – Output “C” - Receive 6 bytes (YY+MM+dd+hh+mm+ss) Receive 6 bytes (Sets+YY+MM+dd+hh+mm+ss+Status+Sample rate+Records) Get Record – Output “K”+N records” st nd Receive (YY+MM+dd+hh+mm+ss+Status+Sampling rate+Records+1 record+2 record+…+nth record) Erase Command: “EEE” (3 bytes) Switch Fast/Slow: “F” (1 byte) Switch A/C: “A” (1 byte) Switch range: “U” (up), “P” (down) (1 byte) 12 Set MAX spl; “M” (1 byte) Stop Recording: “T” (1 byte) Start Recording: “S” (1 byte) Model 407764 Version 2.1 9/07