Hook a few of these up to your Raspberry Pi, Arduino or other microcontroller and keep an eye on the temperatures of all sorts of things!

These digital temperature sensors are an inexpensive, no-fuss way to gather temperature readings - whether you're looking to monitor your hot water tank, aquarium, greenhouse, or just ambient air temperature. They use a 1-Wire interface, which means that multiple sensors can share the same data pin - each sensor comes with a unique 64 bit serial code which will let you read them seperately.

The stainless steel casing is waterproof, moisture proof and rustproof.  It's attached to 1m of cable so you get a lot of flexibility about how and where you position the sensor.

Key Features

DS18B20-compatible digital thermometer

1-Wire interface requires only one data line (and ground) for communication  - each device has a unique 64-Bit serial code stored in on-board ROM

Measures Temperatures from -55°C to +125°C (-67°F to +257°F)

Programmable Resolution from 9 Bits to 12 Bits

Parasitic power mode requires only 2 pins for operation (DQ and GND), eliminating the need for an external power supply.

Alarm function with nonvolatile user-programmable upper and lower trigger points

Stainless steel casing (6x50mm), lead length 100cm

Datasheet

Output lead:

Red (VCC)

Yellow (DATA)

Black (GND)