User Manual Noise Dose Meter Model SL400 Additional User Manual Translations available at www.extech.
Introduction Thank you for selecting the Extech Instruments Model SL400. This device is shipped fully tested and calibrated and, with proper use, will provide years of reliable service. Please visit our website (www.extech.com) to check for the latest version of this User Guide, Product Updates, Software, and Customer Support. Safety CAUTION: Avoid taking measurements in humid or wet environments.
Description Meter Description 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Microphone Connector USB Interface LCD Display Power Button Microphone and wind screen Navigation Buttons Start / Pause Button Microphone Cable REC/MEM Button ENTER Button SET Button Stop Button 8 1 3 5 4 6 7 Display Description 6 2 9 10 11 12 Battery Status Auto Power Off Enabled Pause 115dB indicator (SPL) Stop 140 dB indicator (Peak) 3 SL400‐en‐GB_V1.
Start USB Interface SPL High dB Range (70~140) SPL middle dB Range (50~110) SPL low dB Range (30~90) dB level Testing mode Sound Level Meter mode Noise Dose % Sound Level dB unit A weighting C Weighting Z Weighting Fast response Slow Response Impulse Weighting Over Range Under Range Solid: Auto record standby; Flashing: Recording Start test time (begin) View recorded data Stop test time SET mode Test duration 4 SL400‐en‐GB_V1.
Set Mode Press the button to enter set mode. There are a total of seven functions in set mode: Test Mode, Power Off, Sampling Time & Auto Record, Real Time Clock, 94dB Offset Adjust, Noise Standard, and SLM function. Press the SET button to move to the next parameter or Press enter to exit set up mode. Test Mode Set Press the or button to change the test mode between NDM (Noise Dose Meter) and SLM (Sound Level Meter). Press the SET button to move to the next parameter or Press enter to exit set up mode.
Sampling Time & Auto Record Set or button to select either Auto Recording set or Sampling time. or button to enable or disable Auto record (On or Off) or to adjust the sampling Use the time. The minimum sampling time (interval rate) is 1 reading per second. The maximum sampling time is 23 hours, 59 minutes, and 59 seconds. Press the SET button to move to the next parameter or Press enter to exit set up mode.
94dB Offset Adjust (Calibration) See section on meter calibration before proceeding with this parameter. Press the SET button to move to the next parameter or Press enter to exit set up mode. Noise Standard Set Press the or button to select a NDM testing regulatory body abbreviation: OSHA, MSHS, DOD, ACGIH, ISO85, ISO90, and USER. Press the SET button to move to the next parameter or Press enter to exit set up mode. 7 SL400‐en‐GB_V1.
SLM Function Set or Press the , button to change a test function. These include: , and , , , and , and Peak C and Peak Z Press the or button to select the next test parameter: Time weighting (Fast, Slow, or Impulse), Frequency weighting (A, C or Z), Peak frequency measurement (C or Z). Sound level range (high, medium, or low) High – 70 to 140dB Medium – 50 to 110dB Low ‐ 30 to 90dB Press the SET button to move to the next parameter or Press enter 8 to exit set up mode. SL400‐en‐GB_V1.
Calibration Automatic Mode Calibration Set the meter to SLM mode, A weighting, High range, and Slow. Attach a 94.0dB (1000Hz) sound calibrator to the microphone. Enter SET mode and go to the parameter 94ADJ. Press the Run to appear. key to start the automatic offset routine and wait for the flashing dB number Press the Enter key to save the entry and to get back to the measure window. The meter should now read 94.0dB (+/‐ 0.1dB). If the measured value does not equal 94.0 (+/‐ 0.
Manual Mode Calibration Set the meter to SLM mode, A weighting, High range, and Slow. Attach a 94.0dB (1000Hz) sound calibrator to the microphone and wait for about 1 minute and note the sound value on the display. Write down the value. Calculate the value of the offset from the displayed value to the sourced noise level. In this example the value is +1.3 (94.0dB sourced, and 92.7dB displayed) Enter Set mode and go to the parameter 94ADJ.
Operation Sound Level Measurement Procedures Press the button to turn on the meter. The LCD will display the SPL symbol, with SLM on the lower line. If SLM is not visible press SET and NDM will appear, press the Down arrow to change to SLM and press enter to exit. Press the button to scroll through the available test functions for this mode: SPL, Leq, SEL, and PKMAX. Press the button to begin testing. Press the button again to pause testing. .
Auto Data Recording Press the button to enable the auto data record function. The symbol will flash on the LCD display. The bottom left of the LCD display will show WRITE, at each sample interval to indicate that the data was written to the meter’s internal memory. Erase memory When the bottom left of the LCD displays FULL, the internal memory is full. The auto function cannot be used until the data stored in memory is downloaded and cleared.
Noise Dose Measurement Procedures Press the button to turn on the meter. The LCD will display the SPL (sound pressure level icon). If SLM is showing in the lower line, Press SET and press the down arrow to change SLM to NDM. Press the Enter button testing. Press the to exit setup. Press the button again to pause testing. Press button to enable noise dose to stop testing.
View Logged DOSE readings Note: It is best to view the DOSE data from the software interface. Refer to the SL400 Software Help guide. For DOSE noise readings, SLM must NOT appear on the lower line. If SLM appears on the bottom line, change the mode to NDM in Setup mode. Press and hold the Press the or button for more than 1 sec to enter the viewing mode. button to scroll through the Dose recording log.
Definitions Measurement Parameters Test Function Screen parameter Explanation SPL LAFp Sound pressure level (SPL) SPL LASp Sound pressure level (SPL) SPL LCFp Sound pressure level (SPL) SPL LCSp Sound pressure level (SPL) SPL LZFp Sound pressure level (SPL) SPL LZSp Sound pressure level (SPL) Leq LAFq Equivalent continuous level for the duration of the measurement for A weighting Leq LCFq Equivalent continuous level for the duration of the measurement for C weighting Leq LZFq E
Maintenance Battery Replacement When the battery icon ( ) appears on the LCD, the battery must be replaced. Turn off the meter and remove the rear battery cover. Remove battery from the battery holder and insert a new 9V battery (Alkaline) observing correct polarity. Re‐install the battery cover. o Please dispose of batteries responsibly; observe all regulations. o Never dispose of batteries in a fire; batteries may explode or leak.
Specifications Display LCD type (MAX reading 999999) Display Refresh Rate 1 reading/second Standards IEC 61252‐1993 IEC 61672‐1‐2003 ANSI S1.25‐1992 ANSI S1.4‐1983 ANSI S1.
Microphone Diameter: ½ inch Polarization voltage: 0V Dynamic range: 25 dB ~ 140dB Sensitivity: ‐32 ± 3 dB (250Hz 0dB = 1V/Pa) Free field frequency response: ±2dB (25Hz ~ 12.5kHz) Frequency (kHz) Pressure deviation 0.25 0.0 1 ‐0.1 2 ‐0.5 3 ‐0.6 4 ‐0.9 5 ‐1.2 6 ‐1.7 7 ‐2.2 8 ‐2.8 9 ‐3.3 10 ‐4.1 12.5 ‐6.0 Input Interface The front is PLT83RFR, the signal input receptacle 1. GND 2. Power (+) 3. N.C. 4.
