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Posts from the ‘Data loggers’ Category

Data loggers: To Bury, or Not To Bury

Globally, the number one reason for data loggers to fail is flooding. Yet, scientists continue to try to find ways to bury their data loggers to avoid constantly removing them for cultivation, spraying, and harvest.  Chris Chambers, head of Sales and Support at METER always advises against it.  He warns,  “Almost all natural systems, even arid ones, will saturate at least once or twice a year—and it only takes once.”  Still…there are innovative scientists who have had some success.

data loggers

A prototype buriable logger container, made from a paint can, PVC elbow, silicone, epoxy putty, and desiccant. Photo Credit: NDSU | Soil Sciences | Soil Physics

The Good

Radu Carcoana, research specialist and Dr. Aaron Daigh, assistant professor at North Dakota State University, use paint cans to completely seal their data loggers before burying. They drill ports for the sensor cables, seal them up, and when they need to collect data, they dig up the cans.  Chambers comments, “So far it looks promising, but we had a long discussion about the consequences of getting any water in those cans. I don’t know what they were sealing the ports with, but they were pretty confident that they could even dunk their paint cans under water.”  The North Dakota research team buried the paint cans last fall, and Chambers says he’s reserving judgment until spring.  Radu comments, “The picture above is just the concept.  The story will continue in April when we see the North Dakota winter toll.” (See update).

The Bad

Chambers has good reason for his skepticism.  If a logger gets saturated even once, its life will be short.  And even if it doesn’t get completely flooded, there is still risk.  As water gets into the enclosure that encases the logger, the resulting high humidity can damage the instrument.  Chambers says, “If loggers that are mounted on a post get a small amount condensation or water inside, they’ll be fine.  But the buried ones have no escape route for water vapor.  If they get wet or are exposed to water vapor even once, they are going to fail. We’ve seen horror stories time and time again. It’s just not a good environment for electronics.”

One group of scientists tried burying their data loggers in five gallon buckets.

One group of scientists tried burying their loggers in five-gallon buckets.

The Ugly

Chambers likes to relate a cautionary tale about some scientists in Seattle, who buried their data loggers in five-gallon buckets with lids.  They taped their loggers to the lid, but when they dug the buckets up, they were half full of water, and the loggers were dead.  This is because as the buckets filled with water, the loggers were continuously exposed to water-condensing conditions.  After the loggers were repaired, the scientists re-buried them. But, six weeks later, their buckets were again half full of water, and their loggers were dead.

One Success Story So Far

There is one innovative group at Washington State University, however, who can be considered successful.  Postdoctoral research associate Caley Gasch decided she wanted to bury data loggers in the Cook Agricultural Farm, an actively managed field, so they weren’t constantly taking down loggers and causing large gaps in their data.  

Next week: Find out how she was able to solve many of the problems that prevent successful deployment of data loggers underground.

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Philippines Part 2: Overcoming Native Challenges with Remote Data

In one of the first agroforestry efforts in mountainous terrain, Moscow, Idaho community leader Loreca Stauber, Dr. Anthony S. Davis, Tom Alberg and Judi Beck Chair in Natural Resources at the University of Idaho, and their partners have initiated a program where U of I students travel overseas to work with farmers of Banguet province in the Philippines to develop the skills needed to grow high quality tree seedlings.  Local vegetable farmers have historically terraced the mountains that have been forested so they could grow monoculture crops, causing serious erosion (read about it here).  The land has degraded so much that the Philippine government has stepped in: warning farmers to begin conservation techniques, or they will take away the land and manage it themselves.

Remote Data

Building a local nursery in Benguet.

Inspiring Students to Look at the Big Picture

One of the steps in helping local farmers to solve this problem is to create a local nursery where they can start growing native plants and trees.  Fortunately, the University of Idaho has operated a tree nursery for over one hundred years, and they understand how to grow trees. Dr. Davis specializes in setting up native nurseries for growing native plants all over the world. He says, “I want our students to be exposed to this because we’re graduating students who should be problem solvers, who should be able to look at the biggest challenges and contribute their own ideas towards resolving those challenges.”

Loreca Stauber adds, “We are part of the world and the world is part of us. The students can do more than just get their degree and find a job. Anthony and Kea, when they do this, inspire students to look at a bigger world than they are currently living in.”

Training Students to Understand Native Terrain and Resources

Davis says a good plan needs to take local conditions into account:  “The principles of growing trees are actually universal. It doesn’t matter whether you’re in Haiti, Lebanon, Idaho, or in the Philippines. Those principles are the same and they’re readily transferable. It’s how you adapt them to unique local situations that makes a difference.”

Remote Data

“It’s not really about the best way to grow a plant in a greenhouse environment; It’s about the best way to grow a plant that will also survive on its outplanting site.”

Kea Woodruff, former U of I Nursery Production and Logistics Associate, now at Harvard University, says they train the students who go overseas on the “target plant” concept:  designing a growing regime based on what the plant is going to need in its future home. She says, “It’s not really about the best way to grow a plant in a greenhouse environment; It’s about the best way to grow a plant that will also survive on its outplanting site. Determining what the outplanting site is and what each species will need to survive on that outplanting site is what determines greenhouse operations.”

Dr. Davis says you need to consider native resources when doing these types of projects.  “There could be plumbing there, but there’s no guarantee that when you turn the system on, the tap water will come out. That depends on the seasonality of the rains. It’s part of why we wanted the project partners (the farmers) to have data loggers: so we could look at the data together and get a better feel for when water is most abundant and when it’s most scarce, so it can be stored for later use.”

Overcoming Native Challenges with Remote Data

Decagon (now METER) donated data loggers to the program so that Dr. Davis and other people on the team could look at data with the farmers in the Philippines and advise them when to irrigate.  Davis says, “One of the things that’s most important in trying to set up a very remote nursery and manage the production in that nursery from approximately four flights, twelve hours, and twelve time zones away, is knowing what’s going on. There are things that are really easy to ask, like could you send me a picture every Wednesday and Saturday of the nursery, or could you measure the height and the diameter of the seedlings? What’s much harder to tell is how much water is coming in, or what the temperature was during the day or night, because those require people to be monitoring things at a greater frequency than is often possible. If we know how much water is coming into the nursery from rainfall, we can build collection systems so that we can manage where that water goes later on.”

Managing data for both the short and long term is critical, says Davis, because it’s often whether there was rainfall in the predicted amount, and at the right time, that determines whether a seedling establishes or not.

Next week:  The conclusion of our three part series: an interview with Dr. Davis and Kea Woodruff, discussing the cultural challenges of reforestation in different countries.

Acknowledgements:  The SEAGAA agroforestry project in Benguet is agro and forest; the farmers received a grant from the Rufford Foundation based in the UK to build a greenhouse and much of the water catchment system and auxiliary structure that go with a nursery facility.  They also received a sizable grant from the Philippine government to launch mushroom growing as a necessary complement to help support long-term agroforestry. The project is beyond reforestation – it is the growing of trees, shrubs, ground cover, the restoring of watersheds, creating livelihoods, the rebuilding of soil fertility and integrity, the revival of springs which have vanished with the removal of perennial flora, and the restoring biodiversity to bring back the natural checks and balances of a natural ecosystem.

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What is the Future of Sensor Technology?

Dr. John Selker, hydrologist at Oregon State University and one of the scientists behind the Trans African Hydro and Meteorological Observatory (TAHMO) project, gives his perspective on the future of sensor technology.

sensor technology

Dr. John Selker (Image:

What sparked your interest in science?

I was kind of an accidental scientist in a sense. I went into water resources having experienced the 1985 drought in Kenya. I saw that water was transformative in the lives of people there. I thought there were lots of things we could do to make a difference, so I wanted to become a water resource engineer. It was during my graduate degree process that I got excited about science.

What was the first sensor you developed?

I’ve been developing sensors for a long time.  I worked at some national labs on teams developing sensors for physics experiments. The first one I developed myself was as an undergraduate student in physics. I was the lab instructor for the class, and I wanted to do something on my own while the students were busy. I made a non-contact bicycle speedometer which was much like an anemometer. I took an ultrasonic emitter, trained it on the tire, and I could get the beat frequency between emitted sound and the backscatter to get the bicycle speed.

What’s the future of sensor technology?


Right now one of the very exciting advances in technology is communication. Having sensors that can communicate back to the scientists immediately makes a huge difference in terms of knowing how things are going, making decisions on the fly, and getting good quality data.  Oftentimes in the past, a sensor would fail and you wouldn’t know about it for months.  Cell phone technology and the ability to run a station on a few AA batteries for years has been the most transformative aspect of technological development.  The sensors themselves also continue to improve: getting smaller and using less energy, and that’s excellent progress as well.

sensor technology

What often happens is that you install a solar sensor, and then a leaf or a dust grain falls on it, and you lose your accuracy.


I think the next big thing in sensing technology is how to use what we might call “semi-redundant” sensing.  What often happens is that you install a solar sensor, and then a leaf or a dust grain falls on it, and you lose your accuracy.  However, if you had a solar panel and a solar sensor, you could then do comparisons.  Or if you were using a wind sensor and an accelerometer you could also compare data. We now have the computing capability to look at these things synergistically.


What I would say in science is that if we can get a few more zeros: a hundred times more accurate, or ten times more frequent measurements, then it would change our total vision of the world.  So, what I think we’re going to have in the next few years, is another zero in accuracy.  I think we’re going to go from being plus or minus five percent to plus or minus 0.5 percent, and we are going to do that through much more sophisticated intercomparisons of sensors.  As sensors get cheaper, we can afford to have more and more related sensors to make those comparisons.  I think we’re going to see this whole field of data assimilation become a critical part of the proliferation of sensors.

What are your thoughts on the future of sensor technology?

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The Scientific Instrumentation Museum of Horrors

Chris Chambers is the primary technical support scientist at METER.  Deep within the recesses of his office, there is a collection of scientific instrumentation we like to call the “Museum of Horrors”.  It showcases the many instruments that have been mangled and destroyed over the years by insects, animals, or the environment.

scientific intrumentation

This serial cable melted when it got too close to a sample heating oven.

We get a few instruments back every year that are burned up in a fire, chewed up by rodents, and occasionally we get one that’s been exploded by lightning. We interviewed Chris to find out how to prevent scientific instrumentation from being damaged or destroyed by these types of natural disasters.

scientific instrumentation

Beware of ant hills. This soil moisture sensor got eaten by ants.

Animals and insects:

The single most important thing you can do to prevent damage from animals is to protect your cables. You can protect your cables with cable armor, electrical conduit, or PVC pipe. Even better is to place cables in some type of conduit and then bury it.  Keeping things tidy around the data logger and avoiding exposed cables as much as possible will go a long way toward preventing animals and insects from ruining your experiment.

scientific instrumentation

A retired ECH2O10 that was hit by a shovel.


Lightning is not as big of a danger on METER loggers as it is with third party loggers (read about logger grounding here). Where we typically see people run into problems with lightning is when they have long lengths of cable between the data logger and sensor. Long cable runs act like lightning harvesting antennae.  The best thing to do is to keep the cables shorter and do not spread them out in lots of different directions.

scientific instrumentation

This soil moisture sensor was pushed into a rock.


We have a few instruments every year that get burned up in fires, but there is not much you can do about this hazard except for watching for reports of encroaching fires that may be in your surrounding area and evacuating important instrumentation.

scientific instrumentation

data logger that was struck by lighting.


The worst killer of data loggers is flooding.  We have a lot of customers that try and bury their loggers, and that’s generally a terrible idea.  Unless you can guarantee the logger will be waterproofed and put some desiccant inside the box, it will probably end badly.  There are a few scientists out there that have done a really good job of waterproofing, but they generally spend almost as much effort and money waterproofing as they do purchasing the actual logger.

There’s always going to be some risk to your scientific instrumentation because you’re installing it outside, but hopefully, these tips will help you avoid disaster and keep your system out of the museum of horrors.

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Are Arduinos Practical and Cost Effective?

Last spring my daughter, Sarah, needed a project for the science fair, and since she has always been interested in scientific measurements, we decided to try and figure out when it was time to water her mother’s plants. Since we’ve fielded a lot of calls from customers asking about using Arduinos (user-programmable microprocessors) lately, I thought I would kill two birds with one stone and give one a try. My preference would have been the speed and simplicity of a METER data logger, but I was curious about how practical and cost-effective this method might be for taking measurements.


Arduino Science Project with my daughter

The Arduino is an inexpensive, user-programmable microprocessor on a circuit board that has exposed analog inputs for measuring voltages and digital ports for measuring incoming digital signals. It can also run displays and is programmed by an Arduino IDE running on your computer.

I purchased a book called Arduino Recipes that taught us the basics of Arduino programming, which was pretty straightforward. The Arduino board itself has rows of pinheaders, so I brought some of the male pinheaders from work and soldered all the wires to them, in preparation to attach the water content sensor. It looked medusa-like with all the wires coming off the pinheaders, but we could then just hook up kid-friendly snap circuits and try some elementary tests to get used to the system.

We hooked up Decagon’s (now METER) analog water content sensor (EC5)  first and started measuring. It has a really nice calibration equation supplied by METER, so we used that for a while to measure water content. We took one of mom’s dry plants and measured before and after watering and used the readings to make a linear relationship between the reading on the sensor when it was dry and the reading on the sensor when it was wet.


Our biggest challenge was that Sarah wanted to display this to mom to make sure she knew when to water the plants. So she and I then had to figure out how to integrate an LCD display.

Sarah was excited to get the digital soil moisture sensor integrated because we could then measure water content AND electrical conductivity (EC) to get an idea of the fertilizer in the soil. We used my work colleague’s code to read the digital sensor output, which worked quite well.  It only took a few minutes to insert his piece in the code into our program and start reading water content. Our biggest challenge was that Sarah wanted to display this to mom to make sure she knew when to water the plants. So she and I then had to figure out how to integrate an LCD display. Luckily, all the details were on the Arduino website.  We just cut and pasted the code into our program and then did all the wiring.

Finally, we had it all put together, and we inserted the 5TE digital sensor into the pot. It worked, but the device was large and unwieldy. Mom wasn’t happy that we were putting it right in the middle of her clean living room, but Sarah pointed out that we have to make sacrifices for science, so we put the sensors in the soil, set up the display, and ran it for about a week. Sarah took water content data morning and night and watered it when it reached our “dry” point. She took the finished system to the science fair and was excited to find a few future customers.


The biggest challenge would be all the details in the system. We’d need a circuit board, a power supply, a data logging interface board, and a box to put it in, and if we were going to set it outside, that box would have to be waterproof.

Are Arduinos practical for use in your experiments?

It depends. Sarah and I found out that it just doesn’t take a lot to integrate a sensor into the Arduino system and be able to make measurements. However, if we were to try the above experiment long-term, the biggest challenge would be all the details in the system. We’d need a circuit board, a power supply, a data logging interface board, and a box to put it in, and if we were going to set it outside, that box would have to be waterproof. We’d also need ways to connect the sensor to the circuitry, and all these things take time and resources. For me, the take-home message was that Arduinos are a lot of fun, and might fit your application exactly the way you want. However, you’ll need time (often a lot of it) to spend making sure it’s waterproof, doing all the programming, writing a code durable enough to fit your field applications, and getting the hardware prepped. In fact, Decagon support staff take calls every week from frustrated do-it-yourselfers who’ve found this is not as easy as it seems. Thus, in my opinion, an EM50 or Campbell Scientific data logger are more practical options than an Arduino-like microprocessor.

Are Arduinos cost effective?

A lot of scientists want to make measurements out in the field with small budgets. I am certainly one of those. Arduinos are $85 versus a complete data logger that costs several hundred dollars. However, people tend to forget that things like labor even cost discrepancies.

So, if you have plenty of time, want the versatility, and you love this stuff, go ahead and make an Arduino sensor, but at the end of the day, the cost shouldn’t be a driver, because there are data loggers that can do the job of an Arduino more simply and quickly, without all the hassle.

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Solving the Problem of the Disappearing Science Lab Technicians

One of the hardest issues university researchers face today is the lack of funding for lab technicians. Although it’s frustrating that universities are no longer able to support this type of personnel, can technology close the gap? This is a question we’ve tried to answer in our Desert FMP project in collaboration with BYU.

lab technicians

Source: Job listings for Science Lab Technicians have decreased 38% from March 2013-March 2014

I was talking to my colleague, Rick Gill, several weeks ago, and he had this to say about the disappearance of the previously indispensable lab technician: “We have fewer people in the lab, and the people we have are more expensive. We need to be deliberate in how we use their time. If we can make the entire system more efficient using technology, we’ll use the people we have in a way that is meaningful. In ecology right now, one of the things that we’re beginning to recognize is that the typical process where the lab tech would go out and take ten samples and average them is not what’s interesting. What’s interesting is when it’s been dry for four weeks, and you get a big rain event. This is because the average for four weeks is really low for almost all processes, but the data three days after it rains swamps the previous four weeks. So the average condition means almost nothing in terms of the processes we’re studying for global change. We need technology to take the place of the technician who would be monitoring the weather and trying to guess when the big events will occur.”

To capture these pulses in the Desert FMP project, we’re using a continuous monitoring system that communicates feedback directly to us as the principal investigators. Using advanced analysis techniques, we can painlessly assure that data are being collected properly and important events are never missed. Although we don’t have a technician, the goals of the project are still being met.

What do you think? How have you dealt with the disappearance of the lab tech?

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