THE DYNAMIC CALIBRATION OF CYCLE ERGOMETERS

The components of our rig, which is used for the dynamic calibration o f cycle ergometers, were purchased for $4,080 (USA); interfacing the i nstrument with a computer and printer increased the cost by an additio nal $2,550 (USA). The rig is essentially a torque balance and was ther efore validated against the primary measurements of: angular velocity (rev min(-1)), distance (m) and mass (kg). Summing the inaccuracies as sociated with these 3 measurements yields a worst case error of only 0 .3%. The coefficients of variation for a dynamic calibration rig and m echanically braked Monark cycle ergometer assembly ranged from 0.6 to 3.2% for 6 trials at each of the following power outputs: 117.7, 176.6 , 235.4, 294.3 and 353.2 W. The instrument therefore has a high degree of precision.