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Which TFA Dostmann hygrometer to buy

Updated: October 2026

You are looking at five analogue TFA Dostmann hygrometers on amazon.co.uk, and the photos make them look like one dial in different frames. The useful split is the job: a no-battery indoor glance, a model whose English page says synthetic-hair, or the one indoor-outdoor dial. Price comes after that. This is the decision order for the [TFA Dostmann hygrometer comparison](/hub/climate-measuring/tfa-dostmann-hygrometer). The cloth, mould, and any single winner stay on other pages. Prices and stars were captured on 15 October 2026. Products Compared read the listings and TFA’s English pages, and did not run a lab. A qualifying amazon.co.uk purchase can earn us a commission at no extra cost to you.

You are looking at five analogue TFA Dostmann hygrometers on amazon.co.uk, and the photos make them look like one dial in different frames.

Our top picks

TFA TFA 45.2027 indoor hygrometer

Best overall

TFA TFA 45.2027 indoor hygrometer
8.0/10about £17.39
View offer
TFA TFA 45.2045.02 indoor-outdoor hygrometer

Best value

TFA TFA 45.2045.02 indoor-outdoor hygrometer
7.9/10about £9.71
View offer
TFA TFA 45.2024 metal-ring hygrometer

Alternative

TFA TFA 45.2024 metal-ring hygrometer
7.5/10about £10.94
View offer
On this page
  1. 1.Three jobs, then the price
  2. 2.What each listing actually commits to
  3. 3.Two easy mistakes
  4. 4.What this page will not decide

Three jobs, then the price

Four listings are indoor instruments: the 45.2024, the 45.2041.42, the 45.2027, and the 45.2043.51. Their bullets name a house, a basement, or a garage. Only the 45.2045.02 says indoor and outdoor, with a bullet span down to −30 °C. A bedroom stays with the four. A shed wall or an outside mount is the 45.2045.02. The second job is the movement name, and only where an English page uses it. TFA’s English pages for the 45.2027 and the 45.2043.51 say synthetic-hair, which is why they sit at £17.39 and £17.96, against £10.94 and £11.81 for the small metal-ring dials. The synthetic-hair and spring page keeps that wording. It is not a licence to write the phrase on the other three. The third job is a battery-free indoor glance when you do not need the phrase. The 45.2041.42 says no batteries are required. The 45.2024 is the awkward card: the attribute says batteries are required and names no type, while UK reviews describe no cell. It is still the small German indoor dial with the large file, 4.1 from 3,045, at £10.94. The 45.2045.02 is cheapest at £9.71, and that price belongs to the outdoor branch.

What each listing actually commits to

Battery, origin, and regeneration are the lines worth reading after placement. The 45.2041.42, the 45.2027, and the 45.2043.51 say no battery, the 45.2027 in a German attribute line. The 45.2024 says batteries are required and names no type. The 45.2045.02 says no batteries and also prints 1.5 V with no cell named. Origin is Germany on the 45.2024, the 45.2041.42, and the 45.2027. The 45.2043.51 says Germany in the bullet and has no country-of-origin attribute. The 45.2045.02 says China. Regeneration is every 6 months on the 45.2045.02, and regularly, with no interval, on the 45.2041.42. The other three listings are silent. The wrap itself is on the how to regenerate a TFA hygrometer page. Two size pairs refuse to merge, and so do two temperature pairs. The 45.2041.42 title is L 120 × W 29 × H 235 mm against a 7 cm item length. The 45.2024 title is L 71 × W 23 × H 71 mm against an attribute of 23 × 70 mm. The 45.2041.42 bullet says 0–50 °C and the lower attribute says 18 °C. The 45.2045.02 bullet says −30 to 50 °C and the lower attribute says 30 °C.
TFA TFA 45.2027 indoor hygrometer

Testsieger

TFA TFA 45.2027 indoor hygrometer
8.0/10about £17.39
View offer

Two easy mistakes

The 45.2027 is easy to treat as an English-scale dial because the English product page says synthetic-hair. The amazon.co.uk title says German, and a UK review says the scale was printed in German. You can buy it for an indoor room if you can read that scale. The English page does not promise English words on the face. The 45.2045.02 is easy to file under Germany because the other four say Germany. Its country-of-origin attribute is China. At £9.71, with 4.2 from 1,248 reviews, it is a real option when the job includes outdoors, and a weak default when you wanted the small German indoor dial. The 45.2041.42 is the weak twin: 3.8 from 575 at £11.81, with UK reviews of a rattle and a thermometer that did not work. Which listing to open sits on the best TFA Dostmann hygrometer page.

What this page will not decide

A green zone, or Dry, Ideal, and wet on the 45.2043.51, is print. Several bullets show 18–22 °C and 40–60 % humidity. The Centre for Sustainable Energy aims at about 40–60 % and about 18–21 °C. Neither is a UK legal limit, and a reading in the band does not prove a wall is dry. A 45.2020 or a 45.2042 from search is outside these five. None of these dials uses a BS 1363 plug.

Common questions

Which of these five is for indoors only, and which one says indoor and outdoor?
The 45.2024, the 45.2027, and the 45.2043.51 say indoors. The 45.2041.42 has no outdoor sentence. Only the 45.2045.02 says indoor and outdoor, with a bullet down to −30 °C and country of origin China. A greenhouse question on the 45.2027 and the 45.2043.51 is not a yes.
Do any of them need a battery?
The 45.2041.42, the 45.2027, and the 45.2043.51 say no battery is required. The 45.2024 attribute says batteries are required and names no type. The 45.2045.02 says no batteries and also prints 1.5 V.
Why is the 45.2045.02 cheaper, and where was it made?
It is the lowest captured price, £9.71, with 4.2 from 1,248 reviews on 15 October 2026. The country-of-origin attribute says China, and the bullets do not say Germany. The price sits with an indoor-outdoor job, a ±2 °C line, and regeneration every 6 months. It is not a smaller German copy of the 45.2024.
Is the 45.2027 the same dial with English words on the scale?
No. The English page names the movement. The amazon.co.uk title says German, and a UK review says the scale was printed in German.
Can the title size and the attribute size be one measurement?
No. Keep the 45.2024 title and its 23 × 70 mm attribute apart, and keep the 45.2041.42 title apart from its 7 cm item length. Do the same when a bullet temperature disagrees with its attribute.

Related pages

Hygrometer, damp and mould

TFA Dostmann hygrometer

Best TFA Dostmann hygrometer: which listing to open

How to regenerate a TFA hygrometer after unpacking

TFA synthetic hair hygrometer: which page names it

Sources

Manufacturer and public UK sources used for this comparison. Listing prices, stars, and review counts are from amazon.co.uk on 15 October 2026.

  1. TFA — English hygrometer instructions (retrieved 16 October 2026)
  2. TFA — thermo-hygrometers (retrieved 16 October 2026)
  3. TFA — frequently asked questions (retrieved 16 October 2026)
  4. TFA — analogue thermo-hygrometer 45.2027 (retrieved 16 October 2026)
  5. TFA — analogue thermo-hygrometer 45.2043 (retrieved 16 October 2026)
  6. Centre for Sustainable Energy — temperature and humidity at home (retrieved 16 October 2026)
  7. GOV.UK — damp and mould in the home (retrieved 16 October 2026)
  8. Consumer Rights Act 2015, section 9 (retrieved 16 October 2026)