ANSI/ASA S12.69-2010
Federal regulations require the testing of sound emissions from horns located on railroad locomotives.This Standard specifies an alternate method for compliance with the Federal requirements inmetropolitan areas where tests cannot be conducted in an outdoor space free of obstructions. Thedata that result from this procedure are equivalent to those that derive from the procedurepromulgated by the Federal Railroad Administration as described in 49 CFR Part 229.129.