2003-02-04 P & Z Agenda - Laserfiche WebLink

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NTP-l Measurement Procedures NTP-I MEASUREMENT PROCEDURE FOR NON-IMPULSIVE NOISE The following test procedure has been approved by the Executive Director of the Minnesota Pollution Control Agency for the measurement of non-impulsive noise. A. INSTRUMENTATION: >- a sound level meter and a microphone conforming to type 0, I, 2, or S specifications under ANSI S1.4-1983; >- a calibrator of known frequency and level; >- a small screwdriver for sensitivity adjustment; >- microphone windscreen; >- noise survey form; >- Oipod(optionaD B. METEOROLOGY: >- Measurements must not be made in sustained winds or in precipitation which results in a difference of less than 10 decibels between the background noise level and the noise source being measured; >- Temperature and/or humidity conditions must be within the equipment manufacturer's specifications. C. LOCATION: >- Measurements must be made at or within the applicable NAC at the point ofhurnan activity nearest the noise source; >- Measurements must be made outdoors; ;;. Measurements must be made at least three feet off the ground and away from natural or manmade structures which would prevent an accurate measurement (barriers, houses). D. SURVEY PROCEDURE: >- Monitoring must be conducted for at least a one hour time period; >- Calibration must be performed before and after the monitoring period. Adjustments made if necessary; >- Sound measuring devices must use the "A" weighting and FAST response characteristics; >- Background noise must be at least 10 decibels lower than the noise source being measured; >- A survey form must be completed containing date, time, location, noise source, wind speed/direction, temperature, humidity, equipment information (make, model, serial #), site sketch with the location of the noise source and measurement location (including appropriate distances), data and calibration information. A sample survey form is on the following pages. 12