These are standard MQ-2 gas sensors which are sensitive to smoke among other gases. They can be directly connected to ADCs for ease-of-use.
The I2C Touch Sensor is based on FreeScale MPR121, to feel the touch or proximity of human being fingers. This sensor include 2 parts: one Touch Sensor controller, and 4 finger feelers. Insert the connectors of feelers into base of Sensor controller, you can begin your touch controlling.
This product is a high accuracy temperature and humidity sensor used in home conditions.
Sensor is to create Digital (Lo Pulse) output to Particulate Matters (PM).
This Moisture Sensor can be used to detect the moisture of soil or judge if there is water around the sensor, let the plants in your garden reach out for human help.
This Grove-Barometer Sensor features a Bosch BMP085 high-accuracy chip to detect barometric pressure and temperature. It can widely measure pressure ranging from 300hPa to 1100hPa, AKA +9000m to -500m above sea level, with a super high accuracy of 0.03hPa(0.25m) in ultra-high resolution mode.
The sensor is designed for indoor air quality testing.
SparkFun Humidity and Temperature Sensor Breakout - Si7021 is an easy tool,less expensive board that can detect both humidity and temperature.
Thermocouple Type-K - Stainless Steel is a device used for measuring temperature using wires of different metals.
SparkFun BME280 Atmospheric Sensor Breakout measures the differences in pressure found in the atmosphere.