we are working with Mediterranean turtle conservation in Italy, more specifically in Lampedusa.
The biologists there say that one of the weakest points of turtle trackers is the salt water switch, that has to be tuned to a particular level of salinity, and then is bound to fail in the long run due to corrosion etc.
They recommend pressure sensors to have a better longevity and accuracy of prediction when the turtle is at the surface for location captures.
Do you agree with this, and is it possible to add a pressure sensor to the Horizon kit ?
A great conversation regarding turtle tag design. We have experimented with a number of different salt water configurations, and the terminal material, shape and size is also a factor to take into account. To date we found that a larger surface area compared to a smaller pin is much better, but we too are still working on salt water switch designs and hope to share our experiments this year to benefit others.
The good news is that Horizon supports the MS580314BA01-00 pressure sensor and we have tested this at sea on green turtles. It can be soldered to the I2C pad on the board and measurements read back, which can tell you if you are surfacing (rising) and to prepare the GPS or satellite for transmission. It’s not 100% fail safe as the turtles will sometimes float on the surface but extended periods of time, but it can be used to backup the saltwater switch reading.
Here is a link to the sensor on Mouser - https://uk.farnell.com/te-connectivity/ms580314ba01-00/pressure-sensor-14bar-digital/dp/3397827.
Wow fantastic, thanks for the fast and positive answer.
Will look more closely on this.