Inkbird THC-4 LCD Display USB Temperature and Humidity Data logger Recorder Fahrenheit & Centigrade Thermostat with External Sensor Buzzer Alarm

These did work as advertised. However resetting the temperature back after adjusting can be troublesome (at least until I find the trick). They are easy to use and compact. Added value of a display that other loggers do not have unless you spend a good deal more money.

Unfortunately they seem not to stand severe weather conditions

I have used the THC-4 for approximately 960 hours. I have not had a problem. All of my use has been at 40 to 80 degrees and average humidity. The battery life seems ok but that's according to the device. The device give me about how may hours of use is left and seems believable. It gives the hours that the device will work given the sensor time chosen. There is definitely no noticeable unreasonable drain on the battery. I held off buying any recorder as the reviews were so negative. I have found this one does what it says it will do. The software installs easily and does the few simple things it does well, without issue. It's very easy to use or change parameters through the USB when connected to a computer. When I ordered this one which was fairly inexpensive I ordered another very cheap device that did the same thing minus humidity recording. The first one of those I got read err as so as I put the battery in. It never worked. I got another shipped to me at no cost. I did not have to return the broken one. The second one was so hard to open the battery area the screwdriver slot deformed so too broken to use. They are sending me a second. I mention this experience to compare to the Inkbird which was no issue. There are issues in the reviews about Inkbird and the other I bought and in most others for sale, high or low price. At least for me I did not have any issues with the Inkbird and think it a good device for the money.Additional comments:After 5 years of use the TCH-4 is still working fine. I've never had an issue with it. Update March 2021. The battery cover tabs broke off. That is because they were thin and not strong. The cover was very tight to get off and eventually broke the tabs. I have to put the battery cover on with clear tape. I got 5 years out of it and no other issues with it other than the battery door. It still works fine with a taped door so not a big deal to me. It has been a little soldier as far a reliability.

Two units were run under ambient conditions and against a temperature and humidity datalogger for 16,000 10 second samples..Between the two units:Average error was 1 Degree F and 5.1 % humidityMaximum positive error was 3.1 Deg F and 8.3% humidityMaximum negative error was -7.7 Deg F and -1.8 % humidity.When run against a standard ice bath for 16,000 10 second sample test, the units are no longer recognized by the data logging software installed on two different computers.

The software is easy to install and use on a Win7 PC and the hardware itself seems decent for the price point. The external temperature sensor is a nice addition. The included guide could have had a better English translation but aside from that the software works well and exports to different file formats easily, and makes it pretty straightforward how to configure the device parameters for your needs.The configuration page also shows you how many days of logging depth you have based on your chosen time interval which is good to know depending on how long you want to leave the sensor recording data before retrieving the log. There's a Real Time Clock on the device which automatically synchronizes to your computer clock the first time you load the parameters. No comment on battery life yet since I just got it but will update if it is unsatisfactory in any way. The one button operation cycles through different display modes but can reduce battery life if done regularly which is why the unit typically shuts off the LCD shortly after a button press.Would be a 5 star rating if the guide were better translated and if it came with a lanyard to go through the slot in the top that I had to put a zip tie through to hang it, as it has no plastic inlet in the case to accommodate hanging it from a nail or tack.UPDATE: I've downgraded my rating to three stars because apparently this cheap foreign knock-off doesn't even have the data stored in a circular buffer that overwrites old data with new data, so as soon as you fill up the 16,000 data points it just STOPS recording data instead of doing the intuitive thing and OVERWRITE THE OLDEST DATA WITH THE NEW DATA. Seriously a circular buffer is like Intro to Programming 101 first day stuff, this is embarrassing and caused me to unwittingly lose an entire week of data until I realized it wasn't still recording data because it was full so it just gave up on life and did nothing. I suggest buying something made in the US and not something that was clearly cobbled together in the far east.

Works good for my app Directions could be better.

I'm tech literate and this unit was pretty easy to figure out and use. I set it up 6ft off the driveway on the north side of my house under metal awning overhang so it was out of the weather and the direct rays of the sun. I just downloaded the data (every 30 min.) from july 27 2015 to Dec 15 2015 and everything worked great and I exported the data to an Excel workbook. The range in temperature was from 105 deg F to 28 deg F. I don't need this unit to be calibrated or 100% accurate for my use.