Extech Instruments 445815 Big Digit Humidity Alert,White

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?

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!

It keeps the humidity in my toons in check and it is very accurate. I have 3 in the house and they are very helpful.

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.

This item was inconsistent on selecting the modes to change the settings by pushing buttons as shown on the small cover with the instructions on the rear of the meter, difficultly in setting low and high alarm setting because the mode buttons failed to function as they should ,the stand was flimsy.

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.

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.