Project lead: Jose Manuel Lopez Alcala, Marissa Kwon, Miranda Nelson, and Tom DeBell

evaporometer@lists.oregonstate.edu

Evaporometer

OVERVIEW

This environmental sensor system aims to collect, store, and offer near-real-time visualization of the data. It collects relative humidity and temperature, rain and evaporation rates, and has an attachment for collecting albedo data. The whole system is housed in a custom-made 3D printed case, runs on a 3.7V 2500mAh battery, and transmits over a Long Range (LoRa), low power wireless platform. The evaporometer has been updated with improved weatherproofing using conformal coating for all electronics and a weatherproof coating for the 3D printed case. The evaporometer is only the transmitting part of the system; the other half is the receiving end where all the data is acquired and processed for the google spread sheet on which the data is displayed. Here is the link to the receiving hub.

Objectives

  • Collect relative humidity and temperature data

  • Collect rain and evaporation rates

  • Collect albedo data

  • Store all data on SD card

  • Send all data wirelessly

 

Current Design 

The module above allows you to see the most current design of the evaporometer including the albedo attachment. Any save/design change  that we do on our end will be viewable here almost instantaneously. Go ahead and use the cube in the upper right to move the 3D model around to see a 360 view of our design. 

Design Changes

Recently the design has been updated to a more vertical design with the bucket mounted directly on top of the load cell as opposed to being horizontally attached to the electronics case in previous designs as in previous blog posts. In addition, the bucket has been made 2 cm taller to hold a greater amount of water for longer evapotranspiration measurements. This design can help decrease the amount of water falling directly on the electronics case since the bucket is directly above the case. In addition, the self-starting siphon design has been changed to allowing the bucket to drain reliably and in a significantly quicker period of time during precipitation events.

OUTCOMES

The following graphs are the results of the deployment of an evaporometer out in the H.J. Andrews Experimental Forest. Our system was able to run from July to September 2017 without any troubles, but towards the end of September, our system stopped functioning. We are still unsure of the reasons why our system stopped, but one of our sensors indicated that the humidity levels inside of the system where at 100%. We hypothesize that our system had too much moisture inside and eventually short circuited. 

It is impressive to see the data come into the spreadsheet so seamlessly. Our system performed very well and collected over 15,000 data sets over the time that our system was operational. All of the raw data can be accessed through the link in the side bar by directly pressing on the graphs above. The graphs were made from the collected data from the H.J. Andrews Experimental Forest deployment. 

FUTURE

We are currently working on a revision of the design to make our system water/weatherproof. Since we are still unsure of the specific reason for our system's failure; we are trying to make our system more robust to be able to deploy it in any environment. The first thing that we are trying to accomplish is to have our electronics isolated from any external ambient exposure. We are also extending the capabilities of the evaporometer to be able to measure albedo; to do this we will be adding two more light sensors to our system. With these two additions in mind, we are currently designing the next iteration of our system. We envision that the next deployment of our systems will be on a bigger scale including more sensor systems and more robust to be able to handle any weather. 

KEYWORDS

Evaporimeter, Evaporometer, OPEnS,  Evaporation, Rain, Rain Rates, Arduino, Feather


BLOG

REFERENCES


 Current evaporometer. Bottom piece is the cap of the electronics case.

Current evaporometer. Bottom piece is the cap of the electronics case.