A few days ago I mentioned John Neilsen Gammon’s post about The other half of the USHCN network – precipitation
In that post I had a picture of the standard rain gauge used by Cooperative weather observers in the USA, shown below.
One of the downsides to the cooperative observer network is that fact that you have to read and empty this gauge manually each day, and if you miss a reading, you get a cumulative total of a days and no way to figure out what the previous days reading were.
A dipstick is used to get the rainfall reading.
Some observers I spoke with during the surfacestations.org survey indicated that if they missed a reading, sometimes they’d “fudge” the reading by going back to the local newspaper or other weather stations online nearby to get a reading. I should mention that most observers are very diligent, but stuff happens. People get sick, they get called away by family or business. It is inevitable with such a labor intensive system. NOAA recognizes this problem and on some (but not all) stations they put in a Fisher & Porter automatic recording rain gauge like the one shown below.
Amazingly, it uses an old paper punch strip recorder and the data must be run through a 60’s era tape reader.
The description from NOAA below describes the process.
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The most common type of recording precipitation gauge is the Fisher Porter (F&P) gauge, developed by the Belfort instrument Company. The Fisher Porter gauge is designed to work for many years in remote and harsh environments. The F&P gauge weighs the precipitation it collects in a large metal bucket. This bucket sits atop a mechanism which converts the weight of the water into the measuring unit of inches and then, every 15 minutes, punches holes in a paper tape, recording the amount of precipitation. In the winter months the bucket is filled with anti-freeze which allows snow and ice to melt and be accurately measured. The observer removes the tape once a month and sends it to the local NWS Office. After reviewing the data the tape is sent to the National Climatic Data Center for archiving. – Click for larger images
I wonder what the observers do with the bucket of anti-freeze when they are done with it? The list of parts and supplies is quite interesting. Lots to break or run out of. When mechanical failures occur, the observer uses the backup standard rain gauge, but that only works if they remembered to empty it. You can read the manual for Cooperative Observer Network equipment here (PDF)
When I visited NCDC in April 2008, I was told about a crisis that developed over this old apparatus. It seems they can’t get the supplies for the mechanism in it anymore and the paper punch rolls were becoming hard to get. I heard later they had a third party company create a solution; a rebuild kit which you can see details on here (PDF).
It isn’t cheap. I’ve heard the cost to be over $1000 for the rebuild kit. Given what you can see in the NOAA FP rebuild procedures manual, it is easy to see how it could cost so much. I sure travel and labor charges alone add up to about the same as the cost of the equipment, assuming that cost is correct.
But as we know, the government can pay exorbitant amounts of money for simple technology, like hammers and toilet seats. For anyone that might be interested, I have engineered a solution that is small, portable, and quite cost effective. It is also calibrated and NIST traceable.
Here’s my Self Contained Automatic Logging Rain Gauge
This unit can be placed anywhere, and log rainfall data for up to a year using the self contained data logger. Simply plug the data logger into the USB port of your Windows PC to download, graph, and export the data using the software provided.
Features:
- Mounts to any flat surface, mounting screws included
- Can easily be post mounted with a square wood plate, pole mounting accessories available
- Built in bubble level for level surface alignment
- Self-emptying tipping-bucket design is exceptionally accurate
- Special metalized tipper coating resists mildew and algae growth
- Easy snap on cover, no tools required, rotate and lock into place
- Self contained logging of rainfall – no wires or external counters needed
- Automatic and unattended operation anywhere for a period of up to 1 year
- Long life Lithium battery included
- Choice of 0.1 inch or 0.2 mm metric models
- Internal calibration adjustment of +/- 2% if desired. Pre calibrated at factory
- Comes with software for your PC to download data, works under Windows 2000, XP, Vista & 7
- Data in comma delimited format can be exported to Excel, Databases, graphing programs etc
- Selectable logging intervals from seconds to days, preset from factory for 1 hour intervals
- Stores up to 32,510 rain tips (325.1 inches or 6502 millimeters) of rainfall
- Rugged wide temperature range: -35 to +80°C (-31 to +176°F)
- Rain collector case is made of UV resistant
- Designed to meet the measurement guidelines of the World Meteorological Organization
Applications:
- Home, school, or business rainfall monitoring
- Remote rainfall monitoring
- Lawn sprinkler delivery monitoring
- Golf courses and other grass management rainfall/irrigation monitoring
- Agricultural rainfall/irrigation monitoring at growing locations
Units come pre-assembled and tested from the factory, ready to deploy, no assembly is required. Mounting screws and leaf/debris strainer is included along with a mounting/placement guide. Tipper unit is locked with a strap during shipping to prevent damage, and can be cut with a scissors or knife prior to deployment. Functionality of the datalogger unit in the field is indicated by flashing red and green LEDs, with an option to flash the red LED every time an event occurs.
Datalogger includes special datalogger software on CD ROM, waterproof cap, long life Lithium battery which allows logging for up to 1 year, and manual.
Sample Data File produced by the Logging Rain Gauge software: Sample_Rain_logger.txt
The data file shows that the logger captures rainfall tips (.01 inch or 0.2 millimeter) per logging interval, in this case hourly:
At $199 USD, it is much more affordable. Details here should you want to get one. If you ever wanted to monitor rain at a location but can’t be there all the time to check it, this unit could be a solution.
That look really great !!!
Cool stuff Anthony.
I’ve always had a question about rain gauges. Are their measurements affected by wind? Ultimately, with a really strong wind, the rain is almost horizontal; how does that rain fall into the gauge?
It would be possible to place a rain guage on a gymbol and control it to face its mouth always into the direction of the rain.
REPLY: Yes, a wind solution exists: http://ine.uaf.edu/werc/wp-content/themes/wercTheme/support/youcha_hydroSlides/tippingBucket_rainGauge.jpg
But NWS does not use it at COOP stations. – Anthony
Steven Mosher, did you catch all that?
/sarc and poke w/sharp stick
REPLY: I think this was meant for another thread – Anthony
Too simple and easy to use for government work. Add a zero to the price and sell it as designed for government use. Be sure to add a zero to the model number and add useless verbage to the instruction manual for the government model,. You can then contribute to resolving California’s debt crisis.
/sarc off
It looks hackable. If you plug a USB extention cable into the datalogger socket, you could power and log the unit in real time with a computer. It would require some programming to acess the USB interface but I am sure there are packaged software that can do that and probably for free,
REPLY: no more hackable than a regular rain gauge. All it takes is a full bladder – Anthony
Congratulations, Mr Watts, what a nifty and elegant innovation! Let me know if you are thinking of logo/brand and have no one…I feel I owe you for the many hours of entertainment on this site. I dare say the price is way too low for your government, given how they associate being bilked with getting a proper product. Let us know too what hoops you have to jump through to compete…frustration for you and a bit of head-shaking for the rest of us, assuming you can keep your good humour!
As for the old F&P gauges – I bet Willis could make a useful boiler out of them.
A tipping bucket gauge is great, except for heavy rain events, than there is
spillage and the rain amount indicated can be off by a large degree.
Still love you gauge though and would purchase one someday.
Oh rain drops let me count thee,
Oh rain drops where are thee,
Oh rain drops when thee are cold,
Oh rain drops when thee are warm,
Oh raid drops let me count thee.
Hail to the rain drops,
Oh hail to thee drops,
Let me count thee,
Flakes are drops by any other name,
Oh rain drops let me count thee,
Oh rain drops wash away,
Let me count thee.
What is the minimum sample time? I have a use if it can do sub-minute or even one minute samples.
Anthony….. You are such a wonderful and delightful embarrassment to our government! Brilliant and pitbull tenacious!
I’d gladly catch a bullet meant for either you or Steve McIntyre, anytime, and die in your arms. …..smile.
If you want an agent selling to the feds, I’ve got a company with a 30 year pedigree and all the govt stamps — plus four times the face value of any PO toward meeting SBA purchasing goals. NOAA would swoon! And, you wouldn’t have to talk to nobody. ….smile.
Write to me, if interested. ….Lady in Red
In Australia this type of rain guage has a problem with birds sitting on them and crapping inside, so they have to be cleaned constantly.
As someone mentioned, there could be a maximum rate beyond which overflowing will mean a lower recorded figure – do you have any data for that? That is, what is the maximum rate that can be accurately measured?
I am also interested in how it would handle very light events – i.e. what happens when it only tips over once every four or five data-logging points? Will this cause strange readings? I guess rainfall at this level this will be so low as not to really matter and I expect the bucket size is chosen as a compromise between these two extremes – maybe there is an option for either altered bucket sizes and/or narrower neck collection vessels to “tune’ the device for different expected rainfall.
But, to be fair, these are exactly the same issues in all rainfall measurements – if the rainfall is so heavy that the bucket fills before you go and measure it, you underestimate. Similarly, evaporation will affect rainfall figures on dry days so there will always be a lack of accuracy at the extremes.
What I like about this is the very simplicity of the data collection – count the bucket-tips in a time period. Something machines (electronics) can do much better than reading a scale or even weighing (scales need calibration). Sadly, I have no use for one of these, but part of me wants to buy one – just for the fun of it!
In Guam we sometimes have little Geckos running in the gauge or junk from the Geckos or other tropical debris blocking the hole for the gauge. When you have a remote gauge it is hard to clean it out as oftern as you would like. We sometimes will get a few inches of rain in one observation as the junk cleared out and all went through the gauge all in one shot. Again don’t get me wrong, tipping bucket type sensors are great, but their limitations need to be considered.
Correct thread – but after that last thread someone needs to hold up their hand and ask Steven “how many fingers am I holding up?”
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Roly Sanders said @ur momisugly May 13, 2011 at 5:51 pm
“In Australia this type of rain guage has a problem with birds sitting on them and crapping inside, so they have to be cleaned constantly.”
I find the birdcrap to be less of a hassle than spiders who like to prevent the bucket tipping action with their webs. Bifenthrin helps, but you need to reapply from time to time. It breaks down quite quickly even in our relatively weak Tasmanian sunshine. Maybe I should paint it black since mine is made of translucent plastic.
What I like about mine is the remote sensor so I can check the results from indoors. Data-logging would be cool.
Anthony, the documentation requirements will kill you. The FAA was using onion skin weather charts at their Flight Service Stations when every TV station in the country had computer graphics displays. The only way they got decent weather map displays was for the regions to go out and buy them themselves. Weather service- even worse. I’m still surprised that they ever got the NEXRADs deployed. I worked with the Program Office (JSPO) on the procurement and it was sad.
The gauge picture looks very similar to my Davis gauge ( same basic “counting” mechanism with the tipping bucket). I am also a Cocorahs spotter with their standard analog gauge. The Davis gauge consistently undercalls relative to the cocorahs analog gauge. As such, I am not a big fan of digital gauge technology at this point
Anthony, have you done comparative data collection to standard analog gauges to test the accuracy of this digital set up?
If we can get Zigby to your electric meter, why can’t we put zigby on these instruments.
Our average precipitation for the year is about 8 inches and not nearly as exciting as our wind. However, your rain gauge might be useful in large gardens, orchards, and vineyards where sprinklers are used. Even better if there was an automated “alert” to shut off and/or switch to another block of crops.
Unfortunately that automated solution is too cheap. As we learned from the thread on the Sandwell wind turbines, the real cost is in the government decision-making, product specification and qualification, and the installation. An inexpensive instrument makes the rest of the process look too costly by comparison. As others have pointed out above, if you want to sell to the gub’ment, add a couple of trailing zeroes to the hardware price.
The bird poop is not a trivial issue – I’m having it with my Davis gauge of a very similar design. What has been happening is that the poop isn’t enough to totally plug it, but the collected rain drains much more slowly.
Haven’t seen spiders in it yet like I did in my plastic gauge all the time, though. But the requirement to empty it daily also required visual inspection daily too.
One solution for the tipping bucket design is to put a ring of spikes around the rim of the bucket, closely spaced so the birds can’t fit between them and pointing upwards so that you’re not just providing more perches.
If you use metal spikes and have a nearby outlet, you could wire alternating spikes as hot and neutral, thus providing cooked snacks while defending your gauge.
Rain here is usually very light. And with very low humidity, was just 10% RH a couple days ago. How does a tipping gauge respond to that? When we get snow, most of it evaporates rather than melts. Ground fog. Does the thing work in very cold conditions?
Of course, we also get the once in 20 year “gully washer”, 10+ inches of rain in a few hours. Haven’t had one in quite a while, back then the water in my street was over a foot deep. And I live on a 7% grade. White water kayaking, anyone?
This isn’t really about this topic, however, being that this is the most recent post.
Can you guys get any info as far as the radiation levels are concerning water, food and of course air levels in the United States, or elsewhere? It seems this information is extremely hard to find, or else it is old, and in data-sets that I can’t make heads or tails of.
Thanks!
Oh and here is the most recent update on the Fukushima disaster:
http://fairewinds.com/content/fukushima-one-step-forward-and-four-steps-back-each-unit-challenged-new-problems
Looks like a nice compact self-contained tipping bucket, great for getting rainfall times and rates. But like the other designs of rain gauges, it has its limitations. The biggest is that it can’t measure snow water equivalent. I’m the co-op observer in a place where more than half the annual precip. falls as snow, so that would be a major issue. I do have a LaCrosse tipping bucket with a plastic funnel that is set up in the summer but comes in during the winter. Another tipping bucket (US Govt issue, left over from some 1970s cloud seeding experiments) has an 8-inch metal funnel, so I can heat it with a couple of 60-watt light bulbs inside. That melts the snow as it falls, but it also evaporates some so snow water equivalent is underestimated, especially for light snow during cold weather.
Two other rain gauges, the CoCoRaHS 4-inch plastic gauge and the cheap (but effective) wedge gauges are also good for cathing wind-blown rain and snow and for swapping out when they fill with snow (since they’re cheap, I have several of each).
But the gold standard remains the 8-inch metal gauge, which can hold two feet of snow or rain, is deep enough that hail doesnt bounce out, and has a large enough opening to get a representative sample of the falling drops and flakes. But it does suffer from evaporation when the sun comes out and heats the copper, and it does have soldered seams than can leak sometimes.
So what’s the bottom line? I have at least five gauges out at all times, each of which has its advantages. Usually they give similar numbers, and when they don’t, you figure out why and determine which number is the best.
If I didn’t have two tiping buckets already, I’d get this one!
REPLY: We have a heater for snow WC melt, BTW – Anthony