Diagram showing thermostat and thermometer probe placement: the thermostat probe stays in the air at tortoise height, while the thermometer probe can follow the tortoises into the substrate.

Sensor Placement in the Cold Frame

Where should which sensors go?

Temperature management

Managing the temperature for European tortoises requires monitoring the base temperature at tortoise height with thermometers, and controlling the greenhouse heater with thermostats.
In addition, the temperature in the cold frame during hot weather is managed by an automatic window opener and by shading and ventilating.

Placing sensors in the cold frame

Thermostat

In the cold frame, the sensor of the thermostat controlling the heater is always hung in the air, just above the ground, close to the tortoises. When setting the thermostat, hysteresis needs to be taken into account. If a borderline low value is set, this can become dangerous during brumation.

Thermometer

Thermometer sensors, however, can „follow“ the animals into the substrate as they sink into brumation; that is, they are pushed into the substrate at tortoise height, to check the temperature at the animals‘ own level and to trigger relevant temperature alarms below 4 °C.

In case any tortoises are brumating at the soil surface, or come up to the surface, the temperature at the animals‘ height should also be measured there permanently, for safety.
There are often discrepancies between the fairly stable temperature level in the substrate and the more variable air temperature at tortoise height, also known as the base temperature.

Diagram showing thermostat and thermometer probe placement: the thermostat probe stays in the air at tortoise height, while the thermometer probe can follow the tortoises into the substrate.
During temperature management in the cold frame, thermostat probes always stay in the air at tortoise height, just above the substrate, while thermometer probes can follow the animals into the substrate as they sink into brumation. In addition, thermometers are always used to check the base temperature, measured in the air at tortoise height.


More on technology for tortoise keeping

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