Stopwatch and Timer Calibrations - National Institute of Standards ...

List of Tables
List of Tables
Table 1 - Metric prefixes (may be applied to all SI units).....................................2
Table 2 - Unit values, dimensionless values, and percentages..............................4
Table 3 - Type I and Type II stopwatch characteristics.........................................9
Table 4 - Legal metrology requirements for field standard stopwatches and
commercial time devices......................................................................22
Table 5 - Comparison of calibration methods.....................................................25
Table 6 - Traceable audio time signals................................................................27
Table 7 - The contribution of a 300 ms variation in reaction time to the
measurement uncertainty......................................................................32
Table 8 - Uncertainty analysis for direct comparison method (digital DUT)
using a land line....................................................................................38
Table 9 - Uncertainty analysis for direct comparison method (digital DUT)
using a cell phone.................................................................................39
Table 10 - Uncertainty analysis for direct comparison method (analog DUT)
using a land line..................................................................................39
Table 11 - Uncertainty analysis for totalize method............................................46
Table 12 - The effect of the length of the measurement time on stability
(based on 25 readings)........................................................................53
Table 13 - Uncertainty analysis of using a calibrated stopwatch to calibrate
another device....................................................................................60
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