WH1081PC discontinued at Maplins

[AndrewNZ]

Mike

There are only some minor differences.
According to my manuals ...
The WS1081 has a shorter range (300ft) than the WH1080 (450ft).
The WS1081 has a rainfall resolution of 0.3mm (up to 1000mm) while the WH1080 has 0.1mm.
The WS1081 has a humidity range of 10% to 99% while the WH1080 has 1% to 99%.

It wouldn't surprise me if these differences are actually due to typing errors. English is not the first language of the manufacturers (obviously) and much has been lost in translation. Eg they refer to mm of rainfall as a volume. Its all very confusing.

I am trying to find out more detail about how these stations work, particularly with regard to how the readings are processed by the sensor suite before transmission to the console. If, for example, you select a data logging interval of 60min, is the logged windspeed the average over that full 60min period or the last 48sec average at the time of logging. If it's the former then the console must be adding up the anemometer switch clicks over that full hour.
Does anyone know more about this ?
I guess I could do an experiment whereby I stop the anemometer from turning during the last 48sec. If the logged value is not zero then the consule must be counting the clicks over a longer period.

[daj]

The WS1081 has a rainfall resolution of 0.3mm (up to 1000mm) while the WH1080 has 0.1mm.

I wonder, is that important to Cumulus -- if it assumes a 'tip' is 0.3mm or is that not relevant

[steve]

The WS1081 has a rainfall resolution of 0.3mm (up to 1000mm) while the WH1080 has 0.1mm.

I wonder, is that important to Cumulus -- if it assumes a 'tip' is 0.3mm or is that not relevant

It must be a mistake, the WH1080 must be 0.3mm per tip like the others. The Fine Offset web site agrees: http://www.foshk.com/en/products/show.asp?id=42

[AndrewNZ]

Steve

You are probably right, the documentation seems to have alot of errors.
I got my WH1080 manual from the Cumulus Wiki, if you go to the main page and look at recent page additions you will see a link to 'Fineoffset user manual'. If you go to page 14 of that manual you will see that the specs indicate a rainfall resolution of 0.1mm for rainfall up to 1000mm. The Chinese engineers seem to be having quite alot of trouble with their English so I wont be surprised if it is a mistake.

May I ask you a question regarding my WS1081. I hope to use the station at a remote site and set it to log data every hour on the hour. I would then download the data to my laptop every month or so. This is proving to be easier said than done though.

How do a set the WS1081 to log data on the hour? I can specify a 60min interval in Easyweather but it seems to be random as to when the interval starts. Whatsmore I found that the interval start time on the console is different to that on the Easyweather data file. For example the console was logging data at 6min past the hour but the Easyweather data file was logging it with a date stamp of 15min past the hour. I have tried using Cumulus 1 and 2 but have still not been able to do it.

[beteljuice]

Beware the word 'resolution'

rainfall resolution of 0.1mm for rainfall up to 1000mm.

What this means is that the console DISPLAY shows 0.0 => 999.9 in 0.1 steps

Same for the earlier post about RH, it's the display NOT the sensor or its range.

[AndrewNZ]

Yes but if the display resolution is 0.1mm doesn't that imply that the sensor resolution is also 0.1mm. Why would you have a display with a resolution of 0.1m when the sensor resolution is only 0.3mm.

[beteljuice]

Why would you have a display with a resolution of 0.1m when the sensor resolution is only 0.3mm.

So that it can display 0.3, 0.6. 0.9, 1.2 ...........

Although sometimes with the Chinese stuff it can mean tolerence. ie. +/- 0.1, but that is unlikely in this case.

You will see it in the blurb of all sorts of techie stuff nowadays - just trying to lift it's profile, and hope you don't read the small print spec.

eg. RH 1 => 100 % - if you can find a sensor that covers that range for less than 10x what you paid for your entire kit, please post the link here !!!!

[AndrewNZ]

Hi Beteljuice
I just checked the definition of resolution with regard to instruments. It is defined as the smallest change in a measured value that the instrument can detect. Its also known as sensitivity. So its nothing to do with whatever you are using to display the data, its what the instrument is capable of. So strictly speaking, if they say the resolution is 0.1mm it should mean that the bucket in the gauge tips after 0.1mm of rainfall. However as Steve pointed out, the specs on the manufacturers web site say the resolution is 0.3mm so its probably some typo or lost in translation problem. If anyone has a WH1080 maybe they could do a test on their gauge to confirm it.
Regards Andrew

[beteljuice]

The actual measure of the spoon(s) on a good day is 0.297333mm (0.011")

Edit: Importer http://www.sparkfun.com/commerce/produc ... ts_id=8942

[Repairman77]

I'm pretty sure all these WH and WS units use exactly the same remote sensors and the same hardware/software in the console unit with the exception of the radio controlled clock data; and the technical data is simply erroneous in some the manuals.
Mike.

[steve]

How do a set the WS1081 to log data on the hour? I can specify a 60min interval in Easyweather but it seems to be random as to when the interval starts. Whatsmore I found that the interval start time on the console is different to that on the Easyweather data file. For example the console was logging data at 6min past the hour but the Easyweather data file was logging it with a date stamp of 15min past the hour. I have tried using Cumulus 1 and 2 but have still not been able to do it.

I know very little about these stations (others have done more experimenting) and even less about Easyweather, but I suspect that you can't control when the logger moves on to the next location (which is how it works) only how often it does it. It doesn't even timestamp the entries, so Cumulus has to work out timestamps by starting with the current time and working backwards - each entry contains the number of minutes since it was first written to, when that value reaches the logger interval, it moves on to the next location.

[AndrewNZ]

Thanks Steve, that interesting.
I have found that Easyweather takes the reading from the WS1081 console and puts it in the Easyweather data file with a time 9 minutes greater than that on the console. So a data set logged in the console with a time of say 1421 is downloaded to the data file with a time of 1430. Its a real puzzle.
I found yesterday that with the logger set to 5min intervals, Cumulus 2 was downloading the correct times to its database, ie the data sets on the console were the same as in the Cumulus 2 database, so thats promising. However at one point Cumulus 2 logged a data set after only 1min and became out of phase with the console but then corrected itself later on after several readings.
In future versions of Cumulus 2 will you be able to set the logger interval times on the Fine Offset stations so you don't have to use Easyweather?
Regards Andrew

[Alanji]

Hi Beteljuice
I just checked the definition of resolution with regard to instruments. It is defined as the smallest change in a measured value that the instrument can detect. Its also known as sensitivity. So its nothing to do with whatever you are using to display the data, its what the instrument is capable of. So strictly speaking, if they say the resolution is 0.1mm it should mean that the bucket in the gauge tips after 0.1mm of rainfall. However as Steve pointed out, the specs on the manufacturers web site say the resolution is 0.3mm so its probably some typo or lost in translation problem. If anyone has a WH1080 maybe they could do a test on their gauge to confirm it.
Regards Andrew

Just setting up my W8681 and can confirm the rainfall increases in steps of 0.3mm.

[steve]

In future versions of Cumulus 2 will you be able to set the logger interval times on the Fine Offset stations so you don't have to use Easyweather?

If someone tells me how to do it, I can look into it. I've managed to write to the memory (in a failed experiment to set the station clock), and I know which location holds the current interval, so I could try just writing to that to see if that's all that's needed.

[Gina]

I've managed to write to the memory (in a failed experiment to set the station clock), and I know which location holds the current interval, so I could try just writing to that to see if that's all that's needed.

That would be very helpful IMO Steve Most things can be set up on the console, but I don't think that can. It would be nice not to have to use Easy Westher.