how to use a hygrometer
Where to put it, what error to expect from a cheap unit, how to keep a small log.
Updated 2026-09-01 · 6 min read
Without a hygrometer, “a damp house” is a feeling. With a cheap one you do not have a laboratory, but you have an order of magnitude and a log. It is the best cost-to-information purchase in the niche.
Both can be several points off. Decisions should follow the trend and room-to-room contrast, not 53% versus 56%.
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10–25 €
Example desktop hygrometer for diagnosis. Without a relative-humidity number every tip is guesswork. Not a lab review.
When: Always, as the first diagnostic step.
Not when: It does not replace a moisture meter or a rising-damp survey.
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12–40 €
Thermo-hygrometer (T + RH together), category example. Dew point needs both numbers. Not a lab review.
When: When you want the calculators on your numbers, not a guess.
Not when: It does not measure moisture in the wall.
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25–50 €
Example room sensors for a multi-day log. A log beats a single reading. Not a professional alarm.
When: Recurring condensation, night-versus-day doubts, two rooms to compare.
Not when: It is not a professional alarm and does not measure the wall.
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70–120 €
Hub for the SwitchBot ecosystem. It does not measure humidity on its own: only if you already use SwitchBot sensors.
When: You already have (or want) SwitchBot meters and need the app / Matter bridge.
Not when: It is not a hygrometer and not the first diagnostic purchase.
View on Amazon.itAmazon.it affiliate link (tag qordac21-21): we may earn a commission, at no extra cost to you. A category example, not a lab review. Amazon.com is not used.
Alduchov & Eskridge, 1996 — Magnus coefficients
Formule di Magnus-Tetens usate per stimare il punto di rugiada. Accuratezza tipica di frazioni di grado nel range indoor.
Accessed 2026-09-01
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