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Analog stopwatch timer8/19/2023 The thermometer would be in 1 or 2 deg increments, calibrated by an outside lab. To satisfy a potential calibration inquiry. It has been proposed that we install a Bi-Metallic Thermometer at the point where the thermocouples are located to compare the meters. We have (2) Honewell Digital Temperature Indicators to monitor and set temperature and a Process Timer that turns off the heat to the oven at the time you set it for. Longer for vessels with false bottoms and/or portsights 110 to 140 minutes.Depending on vessel configuration. Longer for vessels with false bottoms and/or portsightsįinal Bake-360 Deg. 40 to 50 minutes.Depending on vessel configuration. Having completed a search for "Timers" and thinking that some of the responses may be overkill, I would like to present the following from our Coating procedure for Pressure Vessels (Tanks), big enough to work in. You can email me at for further questions. I have not been able to locate one of these. Some nuclear industry contractors make up test fixtures that start the stopwatch and the standard at the same time. There is anohter method that I can look up if needed. You will get very mixed results, and MAY damage the stopwatch. I do NOT recommend measuring the timebase in a stopwatch. When you stop both, be sure to look at the stop watch display to try to stop at a nominal (or close). Be sure you get 4 to 1 or greater Test Uncertainty Ratio. Let them run for an adequate amount of time (do uncretainty caluclations for the combined uncertainty of the counter, the signal source and the operator uncertainty), and allow enough time to minimize the impact of operator uncertainty. Press start on the counter at the same time as pressing the start on the stopwatch. Set the repetition rate of the source to either 1 KHz, 10 KHz, 100 KHz or 1 MHz. Use the start stop function on a frequency counter (I used a H-P 5335A counter). For a standard, use either a time mark generator (such as used for an oscilloscope calibrator) or other suitably accurate signal source. Add this to your measurement uncertainty as operator error. Record the data and calculate a maximum deviation between readings. Repeat this process at least 25 times (I did it 100 times for about 10 seconds each). The simpler method I have used involves first running an experiment with numerous iterations between the operator and the standard wherein you start the stopwatch and standard and the same time and stop the stopwatch and standard when the stopwatch reads exactly 10 seconds. There are a few different methods to do this. I just read your post on calibrating timers and stopwatches.
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