Soil Heat Flux Plate

Implementation of the standard heat flux plate method at the bare soil site pairs of four types of heat flux plates were used table 2.

Soil heat flux plate. However several potentially sig nificant errors may occurwhen using soil heat flux plates in the field. A unique calibration constant is supplied with each sensor. These include heat flow distortion and ther mal contact resistance philip 1961. The plates were installed in random order at 20 cm spacing along a north south transect.

A thin layer of a thermal heat sink compound with λ 0 18 w m 1 k 1 greater than the plate λ m 1 0 w m 1 k 1 did not increase g m in a clay soil but increased g m by 6 in quartz sand. A 6 5 increase in g m was also observed for plates treated with the same heat sink compound in a silt loam soil under field conditions. Introduction the hfp01 outputs a voltage signal that is proportional to the heat flux of the surrounding medium usually soil. Surface soil heat flux density g calculated using a heat flux plate at 0 02 m depth g 2 and the change in heat storage d s estimated from temperature change at 0 01 m depth versus g 2 alone using half hour data collected under 0 10 m tall cool season grass.

In an energy balance installation all sensors must be completely inserted into the soil face before the hole is backfilled. It is typically used for energy balance or bowen ratio flux systems. If a heat flux plate is installed near the soil surface e g at 2 cm depth the plate might overestimate the soil heat flux by more than 20 as demonstrated by ochsner et al. Sites with heterogeneous media may require additional sensors.

Model hfp01 soil heat flux plate 1. To convert this measured voltage to heat flux it must be divided by the plate s calibration constant. These plates differed in size shape and composition sauer et al 2003. Two sensors may provide spatial averaging.

The popularity of this method is due to its simplicity. And peng et al. The soil heat flux at the bottom of this layer is also estimated rather than measured with a heat flux plate. Disk called a heat flux plate or heat flow transducer to measure g sauer 2002.

The soil heat flux gz is commonly measured with passive heat flux plates but self calibrating plates or additional corrections are required to obtain accurate data.