1
TCAV – Averaging Soil Thermocouple
Probe
1. Description
The TCAV is a temperature probe which parallels four thermocouple junctions
into one. One channel is required to measure the output voltage which
represents the average temperature of the four junctions. The TCAV is most
often used to obtain the average temperature of a soil layer for use in
calculating stored energy.
The probe is constructed with type E thermocouple wire (chromel-constantan)
and can be measured with one of the datalogger thermocouple measurement
instructions,
TCSe()
or
TCDiff()
.
TCDiff()
is recommended because it reduces
noise and ground loop problems.
FIGURE 1-1. TCAV Thermocouple Probe
2. Using the TCAV with Soil Heat Flux Plates
The TCAV is used in conjunction with soil heat flux plates to calculate the heat
flux at the surface of the soil. The plates are buried at a fixed depth of between
5 and 8 cm to reduce errors due to vapor transport of heat.
