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== How do I get good temperature and humidity measurements == | == How do I get good temperature and humidity measurements == | ||
The international standard states ambient air temperature/humidity is measured at 1.25 metres above ground level, protected from direct sun radiation (and direct rain), unless you are measuring soil or ground temperatures. Modern Stevenson Screens are uPVC constructed with a black interior (so they do not radiate heat onto the sensors) and a white exterior (so they reflect as much radiation as possible). An air frost is defined as a temperature below the freezing point for water at this height. | The international standard states ambient air temperature/humidity is measured at 1.25 metres above ground level, above soil or grass not paving, protected from direct sun radiation (and direct rain), unless you are measuring soil or ground temperatures. Modern Stevenson Screens are uPVC constructed with a black interior (so they do not radiate heat onto the sensors) and a white exterior (so they reflect as much radiation as possible). An air frost is defined as a temperature below the freezing point for water at this height. | ||
There is a lot of discussion on the [http://sandaysoft.com/forum/viewforum.php?f=16 Homebuilt forum] about different approaches to improving measurements, and the problems with out of the box instrumentation from the different manufacturers. | There is a lot of discussion on the [http://sandaysoft.com/forum/viewforum.php?f=16 Homebuilt forum] about different approaches to improving measurements, and the problems with out of the box instrumentation from the different manufacturers. | ||