We need to measure oxygen and temperature from sea turtle nests. Sea turtle nests are closed underground environments on specific beaches. They are humid environments and have an average depth of 75 cm. The average temperature varies between 20-35 C. We will put the probes inside of the nests and they will stay there for 8-10 weeks. We will take the measurements at certain intervals. The system must be battery-powered since we are going to use them on beaches.
Our initial thought is to put the probes inside the nest and stick the cables up from the nest to the surface. But we are open to your suggestions.
Our questions are: Can we do this? Which hardware and probs we should choose?
Thank you.
Just for fun, I'd take a look at these:
Thermochron
They would handle the temperature logging part of the project.
What does this mean? Someone will walk up to the logger and offload data from it? Or extract an SD card?
Considering the environment you're going to be working in, my suggestion would be to have a completely sealed system and offload any saved data wirelessly with BLE (Bluetooth Low Energy). This would require that the systems not be buried too deeply in wet sand, since water is a great absorber of the signal. But it would solve any problems with corrosion, etc.
There are a number of portable temperature loggers - google will find them !
Your post shows requirements for temperature, but has zero about the oxygen you want to measure. What ranges are you looking for and consider how you will calibrate the O2 sensor in your system. O2 calibration is not that easy.
Our plan is to do air calibration since we won't have necessary equipment on the beach. Oxygen levels are equal or below 21%. Like I wrote it should be battery powered portable system. Sensor will stay in the nest for 8 weeks. We won't be able to dig them up before sea turtle eggs hatch. Either the system will record the data and we retrieve after 8 weeks or we can use a wireless sensor or put the sensor in the nest, stick the wires up from the surface of the nest and connect the cables to the screen.
This is first time for us to do something like this. So we are not familiar with system. Thank you for your help.
You are quite non-specific. You need to decide exactly what you want to measure, how often, to what accuracy. You then need to get sensors that meet your criteria and will survive the environment. You have to decide how you want to collect the data and/or transfer it. Temperature will be easy, gasses hard. You need to decide how you will power it.
Code is non-forgiving and requires exact specifications. I suggest you start with temperature and see how you go. Lots of examples. Choice of board will depend on requirements. Esp32 may be good for low power and wifi/BLE options.
We want to measure oxygen in a closed environment with 5 days or fewer intervals. It is a humid environment with an average 75 cm depth. Sensors will stay in this environment for 8-10 weeks. It will be battery-powered.
What we want is, if possible, a battery-powered system with a memory card (or with memory) that will record the oxygen %. At the end of 8 weeks, we will retrieve the system, connect it to the computer and get the data.
If anyone has other suggestions we are open. Thank you.
We are thinking 5 days or fewer intervals depending on how we power it. An sd card will be perfect for recording.
How do plan on measuring oxygen. Is it dissolved water, or oxygen content in air?
Oxygen content in the air. Closed envirınment.
You didn't answer the first, more important part. How do you plan on measuring the oxygen content?
I will have to ask the obvious question: Have you ever measured oxygen in the air?
Our measuring unit will be the percentage. At least one digit after the comma. But I didn't understand what exactly your question is. Are you asking about the method, device or protocol, etc.?
I measured dissolved oxygen but not in the air or soil. I'm trying to find an effective but economical way to measure oxygen from the environment I specified in my posts.
Unless you calibrated the way you measured and calibrated any devices, you only read what a device told you. If this is good enough for your nest air, then get any device that fits you budget.
That was my question! So you do not have a sensor capable of measuring oxygen content of the air?
Here are a couple: AlphaSense O2-A2 Oxygen Sensor - GasLab.com
https://www.seeedstudio.com/Grove-Oxygen-Sensor-MIX8410-p-4697.html
EZO-O2 Atlas Scientific | Sensors, Transducers | DigiKey
Do any of these meet your requirements?