Hi,
For the studies of human-corpse decomposition (yes, this is for real 
- I want to measure some parameters 1 meter (3-4 feet) deep in the soil. Sensors are planned to be buried in a kind of a ‘cell’ where the corpse is placed, then covered with soil.
I am looking to measure: temperature (T), soil moisture (SM), soil pH and CO2 level - having those sensors connected to a data-logger, accessible from the outside.
I saw the following devices that might suit:
- T + SM - RS485 Moisture & EC & Temperature sensor for Soil, Substrate, Rockwool, Cocopeat
- pH - industrial-Grade-pH-Sensor-MODBUS-RTU-RS485 - Seeed Studio
- Data logger - Sensor Hub industrial-grade 4G Data Logger with MODBUS-RTU RS485 protocol - Seeed Studio
- CO2 - none…?
Some questions, please:
- Does the pH sensor has a temperature compensation mechanism?
- Is the data logger I mentioned suitable, or maybe there is a different one, less complicated for my needs?
- Data logger has only GSM connection, which might be a problem in the research area. Is there a different unit that can be accessed via a cable, Bluetooth etc?
- Any idea for a CO2 sensor for this setting?
Thank you in advance for you support 
Asher