Rather than simply measuring surface temperature, this sensor measures the energy transfer from or to an object in Watts per square meter.

When the sensor is placed against a flat surface, the differences in the rate of temperature changes between the two sides of the sensor are used to determine the flow of heat. Objects warmer than their environment show a positive heat flow, whereas those cooler show a negative value.

Applications

Physics:

• Investigating insulation properties
• Newton's Law of cooling
• Heatflow to cold objects
• Heatflow from hot objects

Biology:

• Heat loss from the body e.g. through clothes; from different parts of the body, etc.

General:

• Heat flow or loss in buildings e.g. through single and double-glazed windows; from different materials used for glazing; different areas of a door; different building materials.

The Heatflow sensor is designed to measure the flow of heat energy between its upper and lower surfaces giving a bi-directional output in Watts/m². The sensing area is a thermopile consisting of 400 thermocouples set in resin for protection.

Tips for use: When using the heatflow sensor, it should be attached to the test surface using adhesive tape or a rubber band, and left in position for at least 2 minutes to stabilise. (Holding it in position with your hand will produce false readings.) If used on a metallic or glass surface which have low emissivity, attach aluminium foil to the sensor with double sided adhesive tape to improve accuracy.