Extech Instruments RHT20 Humidity and Temperature Datalogger

RELIABLE, ROBUST PRODUCT

L’appareil fonctionne très bien mais vous devez acheter des batteries avec votre achat celle qui vient avec ne fonctionne pas. Deux en deux

Excelente manufactura, buen tamaño, el software es muy intuitivo y fácil usar, en general compre lo que describían en el articulo

Purchased this to monitor temperature and humidity in my lab. Was looking for something that was compact, wireless in the sense of not being hard-wired but NOT capable of RF transmission, and a fairly sizeable memory. It comes with a holder that can be mounted to something secure and locked in place.Downloaded the software from the company's website and it installed without issue on my Win7 computers. All configuration must be done through the software, which is kludgey in some regards. You synchronize the logger's clock with your computer's and configure the logger's sample rate and alarm conditions. It does have a battery monitor. As time progresses, we'll see how it works. It doesn't give you any information other than a picture of a battery segmented into quarters. No time estimation until dead which would be a nice feature to let you know when the battery needs replacing.The klugey part is how you enable logging. You have to go through a configuration setup every time you want to start logging. With the temperature/humidity loggers I've worked with in the past, you configure the device once and then download/erase/restart logging through separate commands. With this unit, you download the data through a separate function and then must go into the configuration screen to erase and restart recording. Not that big of a deal, just different. The downloaded data is saved in two files - one, in the native format of the logging program and one in Excel format. The formatting of the Excel file needs some massaging in order to graph the data nicely, but quite do-able.The unit is on the spendy side, but it does what I want, so I'm happy with the purchase.

I wanted to keep track of the temp & humidity in my garage prior to installing a exhaust fan. The unit is well built and comes with several useful accessories. From the front panel you can see current/max/min temp & humidity. You need to connect it to a PC via USB to set the unit's date, time, and logging options. The software installed fine on my Win 7 64-bit PC. I downloaded the latest version from the Extech website. The software works surprisingly well. I was able to quickly set up a logging schedule, set the time on the unit, and switch to Fahrenheit. Many logging options are available, from 1 sample per second (max 4 hours, 32 minutes) to one sample every 24 hours, and everything in between. I used one sample per minute which will last 11 days 8 hours. You can have the unit stop logging after it collected the max # of sample, or overwrite the oldest data. It records temp & humidity simultaneously. After a week of of logging, I connected the unit to my PC and was able to download the data quickly and display it in graph or spreadsheet form. If you export the data to a file, it is a tab separated file, and can be opened in a spreadsheet. Each timestamped (m/d/y h:m:s) temp & RH reading will be in the file. The graphic display can't be saved by the program, but you can screen capture it. Data can also be stored in a propriety format for reading into the software later.On the not-so-great side, You can't do much from the front panel, like change from Celsius (factory default) to Fahrenheit or setup logging, or view previous logs. User manual is sparse (-1 star) and a little helpful. If you're not handy with a PC, this unit may not be for you. The front panel display is a bit confusing, there's some data there I don't understand. No backlight. The battery is one of those expensive non-rechargeable camera batteries, a standard 9V or AA, AA would have been nicer. There are two tiny (easy to lose) screws holding the battery cover in place, but the screws go into a metal sockets, not plastic - thank you Extech for that. The battery cover also looks to be environmentally sealed.Overall, I'm very happy with my purchase and recommend the RHT20.

Works great so far! I haven't used it excessively, but there is not anything wrong with it. It seems reasonably accurate and the included computer datalogging software works well enough. I struggled between giving it 4 or 5 stars because of this.A few quirks:No power button... it stays on at all times! Supposedly the battery lasts 3 months, but I believe that is without recording samples. I will wait and see.Starting a recording requires you to connect it to a computer and set it up. A mild inconvenience instead of being able to just press "Record"User manual isn't great to get started easily, but I was able to figure out the buttons with a little clicking around.