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The only instrument here that publishes the target ranges to aim for

TFA 45.2024

A German-made analog thermo-hygrometer with a metal ring, publishing the optimal indoor ranges it is read against.

TFA Dostmann analog thermometer and hygrometer with metal ring bezel

TFA 45.2024

A German-made analog thermo-hygrometer with a metal ring, publishing the optimal indoor ranges it is read against.

Type
Analog — no batteries
Case
Metal ring
Origin
Completely made in Germany
Comfort zones
Marked on the dial
Stated targets
Optimal temperature 18–22 °C (64 to 72 °F); optimum humidity 40–60%
Mounting
For hanging, indoors only — house, basement or garage
Temperature accuracy
Not stated by the maker
Humidity accuracy
Not stated by the maker
Amazon reference
B0044XII3A
EAN
4009816020284
  • The only listing on this shelf that publishes the target ranges — 18 to 22 °C (64 to 72 °F) and 40 to 60% RH — so the reading means something without looking it up
  • A metal ring rather than a plastic bezel, and German manufacture, both stated
  • No accuracy figure for either measurement

Best for: A hallway or a cellar wall, for someone who wants the comfort band marked rather than calculated

≈ $37
Check price on Amazon

Specifications

Type
Analog — no batteries
Case
Metal ring
Origin
Completely made in Germany
Comfort zones
Marked on the dial
Stated targets
Optimal temperature 18–22 °C (64 to 72 °F); optimum humidity 40–60%
Mounting
For hanging, indoors only — house, basement or garage
Temperature accuracy
Not stated by the maker
Humidity accuracy
Not stated by the maker
Amazon reference
B0044XII3A
EAN
4009816020284

What the maker puts in writing

  • Analog, metal ring, no batteries
  • Completely made in Germany
  • Marked comfort zones
  • Optimal temperature 18–22 °C (64 to 72 °F) · optimum humidity 40–60%
  • For hanging, indoors only

It publishes the target, which nothing else here does

optimal temperature: 18 - 22 °C; optimum humidity: 40% 60%.

Every instrument on this shelf shows a number. One of them tells you which numbers are the right ones.

For a device meant to prompt an action — open a window, run the dehumidifier — that is arguably more useful than a tenth of a degree of accuracy.

And it still does not say how accurate it is

Neither TFA on this shelf publishes a tolerance, and nor do the two professional instruments above them. The four devices here that do all cost under twenty-two dollars.

Availability

Read on the day this page was built: $37 at the American Amazon shop.

Read from Keepa on the day this page was last revised; stock and price both move without notice.

Prices quoted in this text were read on 2026-10-04. The live price is at the top of the page.

The questions that keep coming up

Why do the stated ranges matter?

Because a humidity reading of 45 per cent is only useful if you know whether it is good. This is the only instrument on this shelf that publishes the answer — 40 to 60 per cent, and 18 to 22 °C (64 to 72 °F) — and the other eight leave you to look it up.

How is it different from the other TFA here?

This one is a round dial with a metal ring, for hanging, and it publishes the optimal ranges. The other is an upright case, wall or freestanding, and it names its synthetic-hair hygrometer element. Neither publishes an accuracy.

Analog or digital?

Analog needs no batteries and drifts slowly; digital publishes a tolerance and needs cells. On this shelf the four devices that publish tolerances are all digital except one, and the one analog that does — the LittleGood — also has a calibration screw.

More thermo-hygrometers

  • TFA Dostmann analog thermo-hygrometer, slim upright case with twin dials

    TFA 45.2043.51

    A German-made analog thermo-hygrometer with a synthetic-hair hygrometer and marked comfort zones.

    Type
    Analog — no batteries
    Hygrometer element
    Synthetic-hair precision hygrometer
    Origin
    Entirely manufactured in Germany
    Comfort zones
    Marked: dry, ideal, wet
    Mounting
    Wall mounted or freestanding
    Use
    Indoor only — house, basement or garage
    Temperature accuracy
    Not stated by the maker
    Humidity accuracy
    Not stated by the maker
    Range
    Not stated by the maker
    Amazon reference
    B01KLSUYLK
    EAN
    4009816029379
    • The only instrument on this shelf whose sensing element is named: a synthetic-hair hygrometer, which lengthens with humidity and needs no power
    • Made entirely in Germany, stated, which no other listing on this shelf claims for any country
    • A bullet headed "Precision" that gives no figure — and five of the nine devices on this shelf are in the same position

    Best for: A room where an instrument should last decades without a battery and look like an instrument

    ≈ $40
    Check price on Amazon
  • SwitchBot Bluetooth indoor thermo-hygrometer with app connectivity

    SwitchBot Thermometer Hygrometer Indoor

    SwitchBot's standalone indoor thermo-hygrometer, pairing over Bluetooth to log temperature and humidity history in the SwitchBot app, alongside dew point and VPD readouts. Confirmed with a live offer on Amazon.de; we found the same listing on Amazon.fr but did not confirm a live offer there at the time of checking.

    Measures
    Indoor temperature, relative humidity, dew point, VPD
    Connectivity
    Bluetooth, with data logging via the SwitchBot app
    Power
    Battery-powered, per the listing
    EAN
    0850007706241
    • Confirmed with a live Amazon offer on Germany at the time of checking
    • App logging adds a history graph the basic TFA instrument in this family doesn't offer
    • We found a matching listing on Amazon.fr but did not confirm a live offer there at the time of checking

    Best for: Anyone who already owns the SwitchBot CO2 monitor and wants humidity and temperature logged in the same app, rather than reading a standalone display.

    Search Amazon for this model
  • TFA Dostmann analog dial thermometer-hygrometer with metal ring

    TFA Dostmann Analog Thermometer Hygrometer 45.2024

    A mechanical, battery-free analog thermometer and hygrometer from TFA Dostmann, with color-coded comfort-zone markings on the dial. Confirmed with a live offer and 7+ sellers on Amazon.de; we found the same listing on Amazon.fr but did not confirm a live offer there at the time of checking.

    Measures
    Indoor temperature and relative humidity
    Mechanism
    Analog dial, no battery required
    Display
    Color-coded comfort zones marked directly on the dial
    EAN
    4009816020284
    • No battery to replace, ever — a genuine advantage over both digital instruments in this family
    • Confirmed with a live offer and a well-established listing (7+ sellers) on Amazon.de
    • No mold-risk alarm and no app logging — a plain dial reading only

    Best for: Anyone who wants a permanent, no-maintenance reading on a wall or shelf and doesn't need an alarm, app, or data history.

    ≈ $37
    Check price on Amazon

Elsewhere in the spares drawer

  • CREATCABIN fabric dust cover for tower and pedestal fans

    CREATCABIN Tower Fan Dust Cover 125x60cm

    A generic-sized fabric dust cover for tower and pedestal fans, at 125x60cm (49.2 × 23.6 in). This is a universal-fit accessory rather than one built for a specific reviewed model — check your fan's actual height and base width against this size before buying. Confirmed with a live offer on Amazon.de; we did not find a listing on the other three markets we checked.

    Dimensions
    125cm (49.2 in) tall x 60cm (23.6 in) wide, per the listing
    Fit type
    Generic / universal — not model-specific
    Material
    Fabric, stated dust-resistant
    • Cheap, and confirmed with a live offer on Amazon.de
    • A generic size that covers most tower and taller pedestal fans, rather than requiring a model-exact match
    • Generic fit — measure your specific fan before ordering, since this isn't built for any one model reviewed on this site

    Best for: Anyone storing a tower or tall pedestal fan off-season who has already checked their fan's height and base width fall within 125x60cm (49.2 × 23.6 in).

    Search Amazon for this model
  • DAODEFUL third-party replacement filter for the Xiaomi Smart Air Purifier 4 Compact

    DAODEFUL Replacement Filter for Xiaomi Smart Air Purifier 4 Compact

    A third-party replacement filter, made by DAODEFUL rather than Xiaomi, built for the Smart Air Purifier 4 Compact. We confirmed a live third-party offer on Amazon.de; we did not find a confirmed listing on the other three markets we checked.

    Filter type
    HEPA replacement filter, per the listing
    Compatible model
    Xiaomi Smart Air Purifier 4 Compact
    Source
    Third-party (DAODEFUL), not an official Xiaomi part
    Amazon reference
    B0H3DGGMLV (DE, third-party offer)
    • Built specifically for the Air Purifier 4 Compact rather than sold as a universal fit
    • A confirmed, live third-party offer on Amazon.de at the time of checking
    • Third-party, not a Xiaomi-branded part — no manufacturer warranty coverage on the filter itself

    Best for: Owners of the Xiaomi Air Purifier 4 Compact who are comfortable with a third-party filter and can order from a German-shipping listing.

    Search Amazon for this model
  • AIRx Filters MERV 11 pleated dehumidifier filter, 14 by 17.5 by 2 inches

    AIRx Filters 1.5-7471

    A four-pack of MERV 11 pleated filters, 14 by 17.5 by 2 inches, for new-style Honeywell DR90 and DR120 dehumidifiers.

    Type
    Replacement filter — the only one on this shelf
    Size
    14 × 17.5 × 2 in
    Rating
    MERV 11 compatible
    Quantity
    4
    Fits
    New-style Honeywell DR90 and DR120, part 50070171-002
    Construction
    Pleated, for increased surface area
    Captures
    Pet dander, pollen, mold spores and dust mites, as stated by the maker
    Replacement interval
    Not stated by the maker
    Washable
    No — these are replacement filters
    Amazon reference
    B0CF7T8KF7
    EAN
    0810095107597
    • The only replacement filter on this shelf, and the only product here that publishes a MERV rating
    • Publishes the exact size and the original part number it replaces — 14 × 17.5 × 2 in, 50070171-002 — so the fit can be verified
    • It fits two named Honeywell models and nothing else: it is not a universal filter

    Best for: A Honeywell DR90 or DR120 dehumidifier whose filter is due

    ≈ $60
    Check price on Amazon

All thermo-hygrometers