(1) The employer must make sure that noise dosimetry equipment meets these specifications:

Dosimeters must be equipment class 2AS-90/80-5 of the American National Rule Specification for Personal Noise Dosimeters, ANSI S1.25-1991, such dosimeters are normally marked "Type 2."

Note:	Make sure any dosimeter used is Type 2 equipment that:
	1. Uses slow integration and A-weighting of sound levels.
	2. Has the criterion level set to 90 dB, so the dosimeter will report a constant 8-hour exposure at 90 dBA as a 100% dose.
	3. Has the threshold level set at 80 dB, so the dosimeter will register all noise above 80 dB.
	4. Uses a 5 dB exchange rate for averaging of noise levels over the sample period.

(2) The employer must make sure that sound level meters meet these specifications:

(a) American National Standard Specification for Sound Level Meters, S1.4-1984, Type 2 requirements for sound level meters, such sound level meters are normally marked "Type 2."

(b) For continuous noise measurements, the meter must be capable of measuring A-weighted sound levels with slow response.

(c) For impulse or impact noise measurements, the meter must be capable of indicating maximum C-weighted sound level measurements with fast response.

(3) The employer must calibrate dosimeters and sound level meters used to monitor employee noise exposure:

(a) Before and after each day's use;

and

(b) Following the instrument manufacturer's calibration instructions.

Notes:	1. The employer may conduct dosimetry using an exchange rate less than 5 dB and compare the results directly to the noise evaluation criteria in Table 1.
	2. For measuring impulse and impact noise the employer may also use a sound level meter set to measure maximum impulse C-weighted sound levels or peak C-weighted sound levels.

PDFWAC 296-307-63405

Make sure that noise-measuring equipment meets recognized standards.