M2H Reusable Temperature Humidity Data Logger Multi-Use USB Digital Temperature Recorder 28800 Points High Accuracy Refrigerator Thermometer Logger PDF CSV Report

Works great, high accuracy, and love that it also collects humidity data. If you're looking for a temperature logger this is a great choice. There are also a lot of customization options if you download the frigga software (change the units F/C and set the recording delay).

It says you don't need software on your computer to read the data on it. What they don't say is that you do need software on your computer to set it up. For MacOS, that software is available on the Apple App Store, so that should be safe, right? Sure, until that app then automatically downloads other software directly from their web site, a DMG that contains a PKG, which you are required to install for the device to be configured, which then installs a service on your computer that runs all the time. As root. Then the "Uninstall" application that they provide is a binary command-line application, which Crowdstrike (antivirus, effectively) kills as suspicious. I was able to unpack the PKG file and figure out what it would do and undo that manually, but anyone who isn't a reasonable expert at MacOS administration will just have a process from "Shanghai Dewav IoT Technology Co., Ltd" running on their computer, as root, for eternity. There is just no need for this at all, and it's genuinely suspicious.

Multiple report types. Great information. inexpensive. I have used this to track issues in several buildings. Couldn't have found the problems without this data logger.

Constantly having to change batteries.

I tested these out in a refrigerator and freezer. The logs identified the periodic temp drop from the defrost fan, but that the temp drop was still in the freezing temp zone I need. These are very easy to use, unlike some other loggers I've tired. I just pushed the record button until I got confirmation and put them in the areas to be sampled. The reports were super easy as well. I stopped the data logging with the stop button and attached them to my mac and the reports were auto generated upon connection. Super simple. The only cons are that the battery life in cold conditions is reduced. The one in the freezer was showing low battery after 5 days. The one in the refrigerator had enough to keep going. This is a limitation of the device because of how they decided to power it. Colder temps reduce battery efficiency and they decided to use small batteries that don't offer a lot of run time in cold temps.

The only problem with this logger is the rubber cap on top that makes it hard to plug it securely into a USB port – they should have either made the cap fully removable or included a cable. Otherwise, it seems to be very well constructed. The unit is not rechargeable, but the battery can be replaced; a coin works well to unscrew the battery cover when the time comes. While this logger works without the software, the default functions are very basic: To start it logging, you press and hold the start button until the blue LED lights; a quick press on the start button after that gives you a brief display of the current measurement, but otherwise the screen is blank (presumably to save battery life). Plugging it into the USB port stops data collection and automatically generates the MS Excel and pdf-report files. That’s the 4 star, basic version of the logger. However, If you go to their main website, you can download & install their “Frigga Data Center” software; there’s also a pdf download of the software’s instruction manual. The Data Center software lets you adjust the default time zone, allow the stop button to function (the default condition is disabled), set min/max temperature alarms, look at the data/graphs, and transfer data to the cloud. I had no trouble downloading the software and getting it to run under Windows 10. To me, the added functionality of the software raises this to a 5 star logger. I should note that the software also includes a poorly-explained “21 CFR part 11” feature; it seems that this setting allows you to add password protection to the data file, to create an official record from the temperature/humidity dataset. For so called “cold-chain” use, this feature enables you to create an regulatory record that you’ve kept a medication, or other temperature-sensitive product, under continuous temperature control during storage and/or transport. Although this is not something I personally need to do, I imagine it would be a valuable commercial feature for some.

I'm definitely not the normal target audience for this. I got this to track the weather on backpacking trips to help better understand what temperature range our sleeping gear and clothing is good for so we can pack better. I was a bit disappointed that the manual wasn't included, I had to download it. The 5.5 x 8 inch card with the download information could have contained the instructions. When I printed them out, they're two 5.5 x 8 pages. The device itself seems very sturdy. It's clearly intended for use in more sophisticated application because it has a scannable and human readable ID as well as an expiration date (the battery is replaceable though). Starting the device up and collecting data was easy. The cap could have been designed better - it's in the way when you're plugging the device in to get data. Very awkward if you're plugging into the back of a computer or the side of a laptop. Regular users will want a cable. In addition to a CSV file with all the datapoints, it generated a PDF with a nice graph and summary statistics on one page (the photo shows part of it) and then another page of all the data points. The PDF uses something I've never seen before to prevent data tampering. Very nice! The instructions mention an app that you can use to change the settings, I didn't try this.

Don’t waste your money, as soon as I figure out how to return it I will. It requires two access codes to use and they only give you one… so not sure how you are supposed to actually use it. The website is worthless to navigate or recieve help.