Extech 407780 Operating Manual

User's Guide

Integrating Sound Level Datalogger Model 407780

Introduction

Congratulations on your purchase of the Extech 407780 Integrating Sound Level Meter. The 407780 with programmable integrating time provides precise linearity over a wide range (100dB) and displays Leq, SEL, SPL, MAX-L, and MIN-L measurements. Response time (FAST, SLOW, and IMPULSE) and frequency weighting (A and C) are programmable. The analog output (AC and DC) can be used with headphones, chart recorders or other devices to store data. The 407780 with PC Interface and real-time calendar clock datalogs (stores) up to 32,000 readings for later transfer to PC. Careful use of this meter will provide years of reliable service.

Meter Description

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Model 407780 Version 2.1 09/07

Refer to the diagram on the facing page:

1. 1/2-inch microphone (shown with windscreen)

2. LCD display

3. Power Switch

4. Leq / SEL / SPL select switch

5. RUN / Pause switch

6. Use the UP/DOWN arrow keys to change the measurement preset time.

7. A / C Frequency weighting select switch

8. FAST / SLOW / IMPULSE time weighting select switch.

FAST: 125ms SLOW: 1 second IMPULSE: 35ms with slow decay

9. Press to select MAX MIN recording. Press again to step through MAX and MIN values. Press and hold for 3 seconds to erase the MAX and MIN values and exit this mode.

10. RECORD / ERASE

Record standby: The RECORD symbol appears in standby mode. Recording: The RECORD symbol flashes once per second while recording. Erase data: Press & hold the RECORD/ERASE key for 3 seconds to erase data (the

entire LCD will flash three times).

11. Real time clock with calendar

12. Measuring time selection for Leq and SEL

13. RS-232 interface connector (Located on bottom, not shown)

14. AC output terminal (located on side, not shown) 2 Vrms at 130dB Output impedance 600Ω Max. Output signal uses standard 3.5mm phono jack (supplied). Signal on tip; ground on sleeve.

15. DC output terminal (located on side, not shown) Output: 10mV/dB Output impedance 100Ω max. Output signal uses standard 3.5mm phono jack (supplied). Signal on tip and ground on sleeve.

16. CAL (calibration) potentiometer (located on side, not shown)

17. External DC 6V power supply terminal (located on side, not shown)

18. Tripod mounting screw (located on rear, not shown)

19. Battery cover (located on rear, not shown)

Model 407780 Version 2.1 09/07

Display Description

1. Level range

2. Date information

3. Leq: Equivalent continuous

4. SEL: Sound exposure level

5. SPL: Instantaneous sound pressure level

6. Low-Battery indicator

7. MAX: Maximum SPL value is held during measurement.

8. MIN: Minimum SPL value is held during measurement.

9. INST: Instantaneous of sound pressure level

10. Data recording

11. Measuring value

12. Memory full

13. Unit

14. Frequency weighting (A/C)

15. IMPULSE time weighting

16. When the TIME display icon switches on, the real time clock is displayed. When the TIME icon is off the display shows elapsed time for Leq and SEL measurements.

17. Bargraph (100dB range with 50 segments)

18. Range over

19. SLOW time weighting

20. FAST time weighting

21. Measurement completion of Leq and SEL

22. Measurement interruption of Leq and SEL

23. Leq and SEL readings

24. Under Range

Model 407780 Version 2.1 09/07

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