First Field Test

A project log for OpenDendrometer

a health monitor for trees and fruit

John OpsahlJohn Opsahl 08/18/2022 at 02:190 Comments

The first field test of the OpenDendrometer breadboard development unit went beautifully. It appears that the device hardware and software operated as intended over the ten hour period. 

The dendrometer displacement and battery voltage data collected during the test is plotted in the image below. The battery voltage behavior is as expected. More testing is required in order to make sense of the dendrometer displacement data.

The dendrometer displacement data shows one 16 minute period of negative displacement around 100 minutes and one 12 minute period of positive displacement around 550 minutes. I expect to see cyclical swelling and contraction of the tree over the day due to water transport. It could be interpreted that the one drop and one rise was the expected cyclical behavior captured at very low resolution. Though I will want to see that behavior repeated across multiple days (at around the same times) before I will be confident in that interpretation. 

I have come up with several theories why the dendrometer may not have measured a displacement larger than 0.02mm during the test. 

All are useful insights that will guide further testing. 

Very glad to have gotten this hardware out on a tree so early in the development process. I would not say the unit it looks pretty but recording actual data is most important at this stage.