Calibration of Stopwatches and Timing Devices

1 Page 1 SOP 24 – 2019 Page 1 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 SOP 24 Standard Operating Procedure for Calibration of Stopwatches and Timing Devices 1 Introduction Pu... Open at page → 2 Page 2 SOP 24 – 2019 Page 2 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Prerequisites Verify that the metrologist performing the calibration is trained and proficient in perfo... Open at page → 3 Page 3 SOP 24 – 2019 Page 3 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Caution: C alibration methods do not require opening the case of the stopwatch or timing device. A stop... Open at page → 4 Page 4 SOP 24 – 2019 Page 4 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Preliminary Procedure Ensure proper preparation and operation of the stopwatch or timing device to be c... Open at page → 5 Page 5 SOP 24 – 2019 Page 5 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Table 2. Reference calibration sources. Service Location Telephone Number Radio Call Letters Broadcast... Open at page → 6 Page 6 SOP 24 – 2019 Page 6 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Start the unknown timer at a minute tone and record the reference UTC time as UTC 1. At or after the pr... Open at page → 7 Page 7 SOP 24 – 2019 Page 7 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Calculate and Report the Mean Correction for the Unknown using Eqn. 6. 12 () 2 xx x CC C + = Eqn. (6) C... Open at page → 8 Page 8 SOP 24 – 2019 Page 8 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 the control limits, conduct a root cause analysis or troubleshoot the source of the problems before rep... Open at page → 9 Page 9 SOP 24 – 2019 Page 9 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Table 3. Example Uncertainty Budget Table. Uncertainty Component Description Symbol Source Typical Dist... Open at page → 10 Page 10 SOP 24 – 2019 Page 10 of 10 This publication is available free of charge from: https://doi.org /10.6028/NIST.IR. 8250 Example tolerance evaluation for a 3-hour interval on a device with 0.01 s resolution: 60min 60 s Tole... Open at page →