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FAQ: Difference between revisions
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→How do I get good temperature and humidity measurements
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== How do I protect my rain gauge against spiders or other natural problems == | == How do I protect my rain gauge against spiders or other natural problems == | ||
There is a lot of discussion on the [http://sandaysoft.com/forum/viewforum.php?f=16 Homebuilt forum]. | There is a lot of discussion on the [http://sandaysoft.com/forum/viewforum.php?f=16 Homebuilt forum]. | ||
== How do I get good temperature and humidity measurements == | == How do I get good temperature and humidity measurements == | ||
The international standard states ambient 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 and a white exterior. | The international standard states ambient 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 and a white exterior. There is a lot of discussion on the [http://sandaysoft.com/forum/viewforum.php?f=16 Homebuilt forum] about different approaches, 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, and the problems with out of the box instrumentation from the different manufacturers. | |||
(If you are using a Fine Offset machine, the thin depth of the thermonmeter/hygrometer should face where your receiver is, for maximum transmission strength, so the wide face is at right angles to the transmission route). | |||
== Pressure == | == Pressure == | ||
Varies with altitude and temperature, but no significant variation with spatial position with regard to nearby fixed bulky objects. Often measured indoors, only consideration will be trying to avoid any forced ventilation or extraction as such air moving systems could have different pressures on intake and outlet sides. Equally operation in close proximity to fast moving (road or railway) vehicles or tunnels can distort readings. | Varies with altitude and temperature, but no significant variation with spatial position with regard to nearby fixed bulky objects. Often measured indoors, only consideration will be trying to avoid any forced ventilation or extraction as such air moving systems could have different pressures on intake and outlet sides. Equally operation in close proximity to fast moving (road or railway) vehicles or tunnels can distort readings. | ||