Appendix B to Part 299 - Cab Noise Test Protocol
49:4.1.1.1.54.9.138.1.116 : Appendix B
Appendix B to Part 299 - Cab Noise Test Protocol
This appendix prescribes the procedures for the in-cab noise
measurements for high-speed trainsets at speed. The purpose of the
cab noise testing is to ensure that the noise levels within the cab
of the trainset meet the minimum requirements defined within §
299.431(h).
A. Measurement Instrumentation
The instrumentation used shall conform to the requirements
prescribed in appendix H to part 229 of this chapter.
B. Test Site Requirements
The test shall meet the following requirements:
(a) The passenger trainset shall be tested over a representative
segment of the railroad and shall not be tested in any site
specifically designed to artificially lower in-cab noise
levels.
(b) All windows, doors, cabinets, seals, etc., must be installed
in the trainset cab and be closed.
(c) The heating, ventilation and air conditioning (HVAC) system
or a dedicated heating or air conditioner system must be operating
on high, and the vents must be open and unobstructed.
C. Procedures for Measurement
(a) LAeq,T is defined as the A-weighted, equivalent sound level
for a duration of T seconds, and the sound level meter shall be set
for A-weighting with slow response.
(b) The sound level meter shall be calibrated with the acoustic
calibrator immediately before and after the in-cab tests. The
calibration levels shall be recorded.
(c) Any change in the before and after calibration level(s)
shall be less than 0.5 dB.
(d) The sound level meter shall be located:
(1) Laterally as close as practicable to the longitudinal
centerline of the cab, adjacent to the driver's seat,
(2) Longitudinally at the center of the driver's nominal seating
position, and
(3) At a height 1219 mm (48 inches) above the floor.
(e) The sound measurements shall be taken autonomously within
the cab.
(f) The sound level shall be recorded at the maximum approved
trainset speed (0/−3 km/h).
(g) After the passenger trainset speed has become constant at
the maximum test speed and the in-cab noise is continuous, LAeq,T
shall be measured, either directly or using a 1 second sampling
interval, for a minimum duration of 30 seconds at the measurement
position (LAeq, 30s).
D. Reporting
To demonstrate compliance, the railroad shall prepare and submit
a test report in accordance with § 299.613. As a minimum that
report shall contain -
(a) Name(s) of person(s) conducting the test, and the date of
the test.
(b) Description of the passenger trainset cab being tested,
including: Car number and date of manufacture.
(c) Description of sound level meter and calibrator, including:
Make, model, type, serial number, and manufacturer's calibration
date.
(d) The recorded measurement during calibration and for the
microphone location during operating conditions.
(e) The recorded measurements taken during the conduct of the
test.
(f) Other information as appropriate to describe the testing
conditions and procedure.