def relaxation_frequency_nitrogen(pressure, temperature, h, reference_pressure=REFERENCE_PRESSURE, reference_temperature=REFERENCE_TEMPERATURE):
    return pressure / reference_pressure * (temperature/reference_temperature)**(-0.5) * (9.0 + 280.0 * h * np.exp(-4.170 * ((temperature/reference_temperature)**(-1.0/3.0) - 1.0 ) ) )
Relaxation frequency of nitrogen :math:`f_{r,N}`.
dataset/ETHPy150Open python-acoustics/python-acoustics/acoustics/standards/iso_9613_1_1993.py/relaxation_frequency_nitrogen