Extech 445815 Hygro-Thermometer Humidity Alert, Dew Point, Calibration

I bought this after much research and I'm sure I have made the right choice.I suffer badly with COPD and I need a more accurate reading of the air quality in my home so I can set my other equipment to fine tune the air for better breathing ....Firstly...It is very accurate and you also have the ability to calibrate it with the appropriate Kit but it is £30,but remember...DO NOT mess with these adjustment screws unless.A) you know what your doing and B) you own the calibration kit,,They are not there to tamper with otherwise and even when using the screws ,only very small adjustments have to be made each time allowing 30 mins between each adjustment if temp and Dew point is essential then look no further..It also comes with an 18" probe which sits on the side in it's own little holder...this is great for those hard to get to places that need to check if damp has set in. It's real easy to set up and it's quick to respond to the atmosphere around it which is handy as you don't always want to leave it hours on end for results...It's also very well made with a small kick stand at the rear to place on any flat surface..You also have the ability to set a high and low humidity (maybe more for those monitoring technical equipment) and also a reset button to see what changes have occured during the day. I will point out that it IS Green with a silver accent and not black as the main photo shows,but it looks quite smart none the less...£40 gets you a great accurate Temp gauge and Dew point monitor and it does a fantastic job.Highly recommended

A nice little until, the temperature seems to be quite accurate, not sure about the % of the relative humidity. The the dew point temperature is accurately calculated between the two figures. Maybe it's a bit over priced for what it is?

No technical advice or comparisons here, I'm no scientist, this monitor works out of the box just pull the tab from the battery compartment to get it started. I needed to find out the humidity levels in the house as it felt cold and a little damp and before investing in a dehumidifier I wanted to see just what was going on, it registered 70% and remained at this level or above for days so I did then invest in a dehumidifier, the interesting thing for me was that this monitor and the reading on the dehumidifier were closely aligned so I knew I did have a damp problem. The dehumidifier did it's job collecting a surprising amount of water, 2 weeks later the humidity in the house is running at 53% and the monitor reflects the same. I know this unit is expensive but I wanted something that gave accurate readings before spending more on a dehumidifier I might not need, I'm glad I bought this it gave the reality needed to understand the house was damp and something needed to happen to make it healthier. There is a lot of science in the other reviews and it does push more for use in computer rooms etc, but if you do want to accurately measure the humidity in your home I would invest in this unit, it's not attractive, it is green but it works and that's all that matters.

It works fine but it's looks cheap.

Expensive but very accurate........you get what you pay for!.........I know it's accurate because I have tested it against my much cheaper Asscom temp/humidity reader/meter, which was showing unrealistically low humidity readings (and this was why I bought the 4X more expensive "Extech"), the difference in humidity readings was 93% vs 65% for the Asscom hygrometer, this is a huge difference and I am 100% confident that the Extech is showing the correct reading (I use it to monitor temps and humidity in a closed terrarium, I use a fogger and it seems impossible for the humidity to be just 65%).........if you need humidity accuracy then get the Extech!

For first two months, it worked well. Then it started to need new batteries about once a week. Then that became about once every 2 to 3 days; then daily. When the batteries needed replacing, various segments of the temp. display were missing. Eventually, replacing batteries (yet again), failed to restore correct display. (Note: new batteries always used: various makes). So I gave up. Since I am an electronics engineer, I opened the item up to look inside - thinking "Perhaps I can mend this". No chance. The build quality is awful: typical Chinese rubbish. So it went into the bin. So, advice: do NOT buy one of these. . . . . I wish I hadn't: . . . . £45 wasted.

Trede loads of other cheap alternatives costing around £10 each but all displayed incorrect results, I know as I purchased four of them at a time. This is the only one that had accurate reading. I checked two of these with test kits and really accurate. It's the old addage isn't it you get what you pay for. So don't wast £40 on other rubbish buy these.

I don't get why folk say these are supposed to be accurate. I checked calibration with a salt solution. I had to increase the setting because it was calibrated too low. Afterwards I bought a Boveda pack and this Extech has to be squeezed inside to fit. Anyway using the Boveda pack I found the hygo was still too low and needed increasing. Mine was about 4% low then. ...To add insult to injury they need calibrating often to keep them right. However I bought two and they both read identical before I started calibrating one. Therefor I am wondering if I have got it wrong. I mean what the hell? To make matters worse there is a calibration option for the thermometer. Sorry but I don't have a scientific lab to get exact temperature with. How the hell can they sell a thermometer and us not expect it to be right? These are basically a con. Basically it appears hygrometers can not be made in a factory and be expected to work accurately, out of the box.

- Calibrated using Boveda - Well-built and BIG digital display...readings can be seen clearly from far away! - ACCURATE and FAST response time, almost INSTANT actually! - TEMPERATURE & RH% readings are very useful in any environment, but it does DEW Point readings as well...which is a BIG plus! - Probe can be detached to take readings behind walls if necessary, which is super convenient & handy - MIN & MAX can be reset, but can also be used to trigger a beeping ALARM which is more useful than it seems - This product only PROVES that EXTECH's already excellent reputation in this industry is WELL-DESERVED and 100% JUSTIFIED - Cheap analog meters do not guarantee fast, accurate & reliable readings...so stop wasting your time and invest in a good HIGH-QUALITY tool like THIS one and say bye bye to those analog meters for good!

Besitze seit Jahren ein Extech 445815, Nachdem ich in der Amazon-Suchmaschine nach Feuchtmessgeräten suchte, fand ich ein optisch ähnliches Gerät mit mobiler Sonde. Hiervon bestellte ich zwei Geräte und ward von der Genauigkeit schwer enttäuscht; wer das Lüften des Kellers und des Hauses ernst nimmt, kann mit TP-Differenzen von 3 Grad nicht zufrieden sein. Dann suchte ich gezielt nach dem Extech 445815, von welchem ich dann drei Geräte bestellte. Die drei Geräte haben eine gute vergleichende Genauigkeit und entsprechen auch dem langjährig benutzten Gerät. Ein Gerät musste in der Temperatur etwas nachjustiert werden - und dann stimmte auch dieses sehr gut. Und nun zu den Vorteilen dieses Gerätes: Das Gerät hat eine relativ sehr gute Grundgenauigkeit - die Grundmesswerte relative Feuchte und Temperatur lassen sich über zwei Potentiometer in Grenzen nachjustieren. Die externe Sonde sorgt für eine relativ schnelle Messwerterfassung (im Gegensatz zu Geräten mit integrierten Fühlern im Inneren des Gehäuses) - und dies ist sehr wichtig zur schnellen Entscheidung über das Lüften insb. des Kellers besonders in den Sommermonaten. Warum gleich mehrere Geräte - diese habe ich im Hause verteilt und eines dient der schnellen Feuchtigkeitserfassung der Außenluft (das Gerät sollte aber nicht dem Regen ausgesetzt sein - leidvolle Erfahrung vor einigen Jahren). Bei mir gibt es keinen muffelnden Keller - dazu muss aber auch die Einsicht der Frau beitragen, dass man bei schwülwarmen Wetter den Keller besser nicht wischt - ein oft mühsamer Überzeugungsprozess.

Il prodotto mi è arrivato nei tempi previsti, amazon è impeccabile. Lo ho testato con termo igrometro professionale (250 € la sola sonda con compensazione barometrica) e ho visto che è arrivato tarato alla perfezione, non è stato necessario intervenire. Il funzionamento è molto semplice. Per questo prezzo è davvero un ottimo prodotto, potete settare allarme della U.R. al valore desiderato, unico allarme è sulla umidità ! Ottimo davvero. Utile per capire quando è ora di aprire le finestre.

We have two and have used them for years to measure both dryness and moisture. The readings differ by just a little bit. I think I returned a third one for being much further off calibration, so it may take a couple rounds when you purchase these. The device allows detach the sensor from the base and thus some ability to measure into places slightly distant from the base. Mostly, though, they reside on furniture and measure ambient air humidity. It does a good job of supplementing my dehumidifier readings as well, as those dehumidifier readings can be way off.

Purchased this instrument to monitor the humidity in our closets and walk-in closet in our home. Some of the rooms within our house have more mildew than others. Took comparison readings of the different rooms and closets. Tried the heating rods in the closets to determine whether these rods help in lowering the relative humidity. Tried running the central A/C system on DRY mode in one of the bedrooms to see whether the A/C works in lowering the RH (relative humidity) and it does. Love the large digital readout and simplicity of use. Moved the instrument among the closets in different rooms of the house to get an idea of the humidity in these areas and to confirm the likelihood and severity of moisture, possibility of mildew development. It's only been about a week of using this meter, but I think it is essential in attempting to control the RH and mildew within your home. Concerned about the electrical consumption of whatever mildew device I utilize, so trying various other processes to see if these work before resorting to a dehumidifier. The hanging Damp Rid fragance free collects a lot of liquid in its pouch, but the RH in the closet has not decreased noticeably at all. The heating rods do not lower the RH quickly and I may need to give this more time. If you want to systematically work towards getting rid of your mildew/mold problems, you should seriously consider getting this instrument.