Description: height of the centre of the inlet pressure gauge; Name: height of inlet pressure gauge 
Description: Height of the zero or centre position of the inlet manometer, or other point as defined by the manometer calibration ; Name: Height of the inlet manometer
Description: Ten times the logarithm to the base 10 of the ratio of the square of the sound pressure, p, to the square of a reference value, p0, expressed in decibels; Name: Sound pressure level