 ISO 18738 specifies measurement methods for elevator ride quality with respect to jerk, acceleration, vibration, and noise; however, the standard does specify levels for acceptable or unacceptable ride quality.It is reported that most passengers rate a vertical jerk of 2.0 m/s3 as acceptable and 6.0 m/s3 as intolerable.For hospitals, 0.7 m/s3 is the recommended limit.