Changes between Version 1 and Version 2 of Ticket #529, comment 6


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Timestamp:
Mar 7, 2014, 9:41:29 AM (11 years ago)
Author:
olle

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  • Ticket #529, comment 6

    v1 v2  
    44 2. The lab environment database should store the following data for a lab sensor measurement:[[BR]]a. Lab sensor number (uniquely coupled to a sensor URL)[[BR]]b. Measurement date/time[[BR]]c. Temperature in °C[[BR]]d. Humidity in %.[[BR]]
    55 3. The tests revealed that the response from a sensor came in a small fraction of a second (of the order of 0.2-0.4 seconds), but the time stamps obtained from the responses of the different sensors could differ more than a minute from each other and the system time of the server, where the test program was executed. In order to simplify investigation of environment measurements from different labs at specific time points, it is recommended that the server system time is used, when a time is stored for a measurement.
    6  4. The API for the lab environment database should allow retrieval of data for a chosen sensor number between specified start and end times:[[BR]]a. If no start time is given, all data for the chosen sensor before or equal to the end time is retrieved.[[BR]]b. If no end time is given, all data for the chosen sensor after or equal to the start time is retrieved.
     6 4. Tests also revealed that subsequent sensor temperature measurements a few seconds apart may fluctuate in a range of 0.5 °C, and the humidity measurements in a range of 0.2-0.5 % units, making detailed comparisons of values within this range be of very limited use. When storing lab environment values, it might therefore be considered to collect measurements during a small time interval (some minutes), and then store the arithmetic mean values. An alternative is to leave it up to the routines displaying or otherwise investigating the values, to make any averaging of the raw data.
     7 5. The API for the lab environment database should allow retrieval of data for a chosen sensor number between specified start and end times:[[BR]]a. If no start time is given, all data for the chosen sensor before or equal to the end time is retrieved.[[BR]]b. If no end time is given, all data for the chosen sensor after or equal to the start time is retrieved.