16-12-2015, 18:13
Looking at the graph I don't see abnormal problem.
Rain rate is calculated based on the time between successive tips of the rain collector.
If there have been no rain tips since the last rain rate data transmission, then the rain rate based on the time since that last tip is indicated. This results in slowly decaying rate values, instead of showing a rain rate which drops suddenly to zero. This results in a more realistic representation of the actual rain event.
If this time exceeds a defined amount of time, than the rain rate value is reset to zero.
As you can see on your graph, despite you say that was continuously raining, between 2:50 and 3:00 there isn't any rain tip, this causes the reset of the rain rate to zero.
This will happen many times during low rain fall rate periods. If you want improve this, you need to improve the quality of your rain gauge to a unit of 0.1mm per tip, and even so a zero rain fail rate can be computed many times under very low rain fall rates.
There isn't a standard for the rain fall rate calculation, the WeatherDuino Pro2 try to follow the Davis approach.
I was looking to the graphs in your website, which I think are still from your other weather station, and I saw that the rainfall rate is only reset to zero, two hours (3:49 - 5:59) after the last rain tip registered.
As said there isn't a standard for rainfall rate presentation, but two hours seems very excessive.
...If this time exceeds roughly 15 minutes, than the rain rate value is reset to zero. This period of time was chosen because 15 minutes is defined by the U.S. National Weather Service as intervening time upon which one rain "event" is considered separate from another rain "event".
Rain rate is calculated based on the time between successive tips of the rain collector.
If there have been no rain tips since the last rain rate data transmission, then the rain rate based on the time since that last tip is indicated. This results in slowly decaying rate values, instead of showing a rain rate which drops suddenly to zero. This results in a more realistic representation of the actual rain event.
If this time exceeds a defined amount of time, than the rain rate value is reset to zero.
As you can see on your graph, despite you say that was continuously raining, between 2:50 and 3:00 there isn't any rain tip, this causes the reset of the rain rate to zero.
This will happen many times during low rain fall rate periods. If you want improve this, you need to improve the quality of your rain gauge to a unit of 0.1mm per tip, and even so a zero rain fail rate can be computed many times under very low rain fall rates.
There isn't a standard for the rain fall rate calculation, the WeatherDuino Pro2 try to follow the Davis approach.
I was looking to the graphs in your website, which I think are still from your other weather station, and I saw that the rainfall rate is only reset to zero, two hours (3:49 - 5:59) after the last rain tip registered.
As said there isn't a standard for rainfall rate presentation, but two hours seems very excessive.
...If this time exceeds roughly 15 minutes, than the rain rate value is reset to zero. This period of time was chosen because 15 minutes is defined by the U.S. National Weather Service as intervening time upon which one rain "event" is considered separate from another rain "event".