For a species as sensitive to its climate as the red-footed tortoise, measurement is the foundation that every other piece of technology builds on. You cannot manage what you cannot see, and relying on how the enclosure feels to a hand is a recipe for slow, unnoticed drift into conditions that harm the animal. Accurate thermometers and hygrometers are the first tech purchase to make.
The most useful monitoring tools give you readings at multiple points rather than a single spot. Because the enclosure is deliberately built with a warm end and a cool end, a humid zone and a drier one, you need to know the temperature at the basking spot, the temperature at the cool retreat, and the humidity in the main living area all at once. Digital units with remote probes make this practical without disturbing the animal.
Accuracy and reliability separate good monitoring gear from decorative gauges. The cheap analog dial thermometers and hygrometers often bundled with enclosures are notoriously inaccurate, and an inaccurate reading is worse than none because it breeds false confidence. Digital probe instruments, ideally ones you can verify against a known reference, are the standard to aim for.
For spot checks, an infrared temperature gun is a valuable complement, letting you read the surface temperature of the basking rock, the substrate, or any specific point in seconds. Together, fixed probe monitors for continuous ambient readings and a handheld gun for targeted checks give a complete picture of the climate the tortoise actually experiences.