Weighing about 50g, the device called SENSg measures and stores data which can shed light on our activities and the environment.

Examples of data that can be collected: Pressure: The pressure reading gives an estimate of altitude. It can show, for instance, the height above sea level one is at.

Relative humidity and temperature: An infrared thermometer provides non-contact temperature- sensing. The relative humidity and temperature of a particular location can provide useful information for the authorities, such as which areas are hotter.

Light: The device contains a photodiode which measures light by converting it into digital signals.

The light level can help to indicate if the participant is indoors or outdoors. Light, temperature, humidity and motion data would help to tell a participant's mode of transport.

Sound pressure level: A microphone in the device converts acoustic pressure waves into electrical signals and provides sound pressure levels in decibels.

Typical ambient noise in Singapore hits 80 decibels during daytime and 55 decibels at night.

Research has found that a constant noise level of more than 80 decibels is associated with increased risk of permanent hearing loss.

Step count: By counting the number of steps, more can be understood about how active the participant is.

Carolyn Khew