GeeBat DS18b20 Waterproof Temperature Sensor Digital Temperature Probe Thermometer Length 1M for Arduino Refrigerator Lab Car (Pack of 5pcs)

I received these, used a sketch I found to obtain the addresses of each, then connected them all up together to verify their accuracy. I was surprised when one was reading over 200 degrees F. I grabbed the sensor and it was hot. I disconnected it and thought maybe it had been in contact with my soldering iron. I allowed it to cool and reconnected it with the rest. I found out that it likely has a short inside. It heats up when connected, though surprisingly, it still reports temperature and doesn't affect the other 4 that are in parallel, nor did it cause any issues with my NodeMCU microcontroller I had them connected to.Amazon was quick to refund my money and I have ordered a new set. Hopefully, they will all work.I'm not blown away by the accuracy. In iced water, there was about 3 degrees variance between them, though that disappeared when the metal tip was placed into hot (160F) water where they were within 1/2 degree of each other. Still, good enough for what I'm using them for.

These are just great, especially for the money. Some have complained that they don't have the 4.7K resistor built-in. This is actually a good thing because without this resistor built-in you can use multiple sensors on a single pin. They are not marked with addresses so you will have to connect them and warm them with your hand one-by-one to figure out what order they are on the bus.I used 5 of these on a project...using just one signal pin. In theory you could get a oneWire display and run a 10 sensor thermometer setup with readout using a single digital pin!They seem to be pretty accurate too; connecting 5 at once the total difference between the readings was just 0.3 degrees C...and removing the one that seems to read low the difference was just 0.1 degrees C. If you have ever tried to work with thermistors and resistors you know just how difficult this is to pull off.

I connected the five units to a Raspberry Pi to test them and get the serial numbers so I could label them. I was pretty surprised with the results.In a room with a temperature of about 70 degrees fahrenheit (21C), the two closest units were about .7C apart (about 1.25F) which isn't too bad but not great. The four closest were about 2.22C apart (4F) which makes them suspect. The really killer was the outlier; it was a full 14C high (about 25F) so it's basically unusable.I was going to return them, only to find out that "THIS IS NOT RETURNABLE".I'll not be buying any more of these.

I'm very disappointed in this product. I needed it to work of parasite power - and they don't. Also, the temperature reading was off by 1 Celsius at room temperature which is 100% more error than spec'ed by Maxim. I got other versions from Amazon, and they worked as spec'ed both for parasite power and max temperature error. I think they must be counterfeit chips to perform this badly. Amazon is not letting me return this junk, despite being listed as Prime. Stay away unless you power these off separate Vcc wire and don't mind inaccuracy.

Working great in my Ardiuno projects. Easy to hook up and they are sturdy.I have them in the furnace and hot water flues and they seem fine.Not sure what temps the cable can withstand but so far so good.The price is competitive with ibay and they get here right away, instead of 2 months from the far east...

i try your product but show temp 214.99 fro room temperature which is equivalent to 101 CI Request one data wire dallas Ds1820 which is working fine but it is not covered, it is not water profIt is possible to convert output of sensor to Celsiusthanks..saleh

These work quite well and the price was low. I would not use these where very high accuracy or precision is needed but are perfect for most temperature measurements.

The wires inside the sheathing are too large to crimp into an RJ45.