Digital 4 Channel Thermocouple Thermometer Temperature Recorder Data Logger AZ Instruments Multi Channel K Type Thermometer Thermocouple Reader with 8G SD Card 2 Bead Type K-Thermocouple Probe

I'm using this to monitor the efficiency of my boiler system. The 4-channels are good. I tested in an Ice bath and boiling water, Using the offset feature, I was able to calibrate all the channels within a couple of tenths of a degree of each other well within the advertised specification. I also compared it to my fluke meter. The unit generates a CSV file when logging. I was able to take the generated CVS file and import to OpenOffice to plot the temperatures in and out of the boiler and each zone to calculate the thermal energy being used by each zone. I was using this to adjust the water flow speed to ensure that the water spent enough time in the pipe circulating in each zone to properly heat my floor.Pros:Uses standard k-type thermal couplers.The display is easy to read each channels tempUses a standard power supply 9V 1.5A Center Positive 5.5mm X 2.1mm connectorLogs to a CSV file, configurable sample rateCons:The display turns off when logging mode is operationalWhile you can figure out the manual, its hard to read poorly translated EnglishThe probes that come with the unit are very short (glad the K-type probes are cheap)All in All, I do recommend this unit.

Works great for displaying and saving (to the included 8GB SDHC memory card) four(4) channels of thermocouple temperature data. Then you need a USB SD-card reader (or some other mechanism) to get the data into your PC. No special software required. The resulting text files are easy to read, and include date, time, and 4 channels of temperature data. Having the 2x2 temperature display, instead of a 1x4 list, really helped in our application. As others have indicated, the readings tend to jump around a bit (perhaps up/down 3 degrees C) in the presence of electrical devices, a design defect which ought to be corrected. Others have complained about the instructions included, perhaps they have been upgraded, they weren't perfect but they were pretty good. We were up and running in short order, and this device paid for itself on the first day of usage. You may as well also purchase "9V 1.5A AC/DC Power Adapter for Arduino, Tbuymax UL Listed Center Positive 5.5mm x 2.1mm Power Supply..." to save on batteries and enable long-period usage. Overall a good product deserving of your consideration.

It's a great option for those non critical measurements that require precise data. Not that this unit is not accurate. It's easy to use and easy to retrieve the data. I don't know how long the batteries last and is my only draw back when I need to run the logger for hours at a time, but so far I haven't had any problems.

The five stars are for the criteria "works as expected for a device at this price point". I have not checked the accuracy extensively—you can likely find other reviews with that information.If you are wondering what polarity and size the 9 V DC power supply plug is, it takes a barrel plug with an OD of 5.5 mm and the center pin is positive (which is information that is not stamped on the device, not in the manual, and not anywhere on the internet I could find).I've used this to monitor a chest freezer in a harsh, alkaline desert environment for about 12 days out of the year for 2 consecutive years now, plus about 10 days of at-home testing and light use.I've only had one issue, which is the SD card became corrupted at some point during the second year in the desert. This was the included SD card. This may have been caused by the batteries running out during operation, or some other cause. This year I am taking a hopefully) more rugged SD card.

The menu system to set up the settings is not good, and the screen shuts off while it's logging so you can't check what the temps are without stopping it logging. Also, it doesn't come with the 120v adapter and as far as I can tell the adapter is not available anymore. So you're stuck with using battery power. Which isn't the end of the world; the batteries do last pretty long while using it. But it does drain the batteries dead while sitting on the shelf turned off, so remove them when you're done using it.But it does work, and as far as I can tell it reads accurately. So if you can get past the clunky interface and battery only operation, it's a good little unit.