Model HFP01 Soil Heat Flux Plate
7
7.3 Programming
Short Cut
is the best source for up-to-date data logger programming code for
the HFP01.
If your data acquisition requirements are simple and you are connecting the
sensor to a pulse terminal, you can probably create and maintain a data logger
program exclusively with
Short Cut
. If your data acquisition needs are more
complex, the files that
Short Cut
creates are a great source for programming
code to start a new program or add to an existing custom program.
Short Cut
cannot edit programs after they are imported and edited
in
CRBasic Editor
.
A
Short Cut
tutorial is available in Section
. If you wish to
import
Short Cut
code into
CRBasic Editor
to create or add to a customized
program, follow the procedure in Appendix
(p. A-1)
.
Programming basics for CRBasic data loggers are in this section. A complete
program example for a CRBasic data logger can be found in Appendix
(p. B-1)
. Programming basics and programming examples for
Edlog data loggers are provided at
www.campbellsci.com/old-manuals
The HFP01 is measured using either a single-ended (
VoltSE
) or differential
(
VoltDiff
) instruction. The differential measurement is recommended.
Syntax of the
VoltDiff()
instruction is:
VoltDiff
(Dest, Reps, Range, DiffChan, RevDiff, SettlingTime,
Integ/FNotch, Mult, Offset)
Syntax of the
VoltSE()
instruction is:
VoltSE
(Dest, Reps, Range, SEChan, MeasOff, SettlingTime,
Integ/FNotch, Mult, Offset)
For the multiplier, divide 1000 by the nominal calibration sensitivity
(1000/sensitivity). The nominal calibration is unique for each HFP01.
Each sensor is accompanied with a calibration certificate and has a label on it
with the calibration values. The label is located on the pigtail end of the sensor
wires.
7.4 Soil Heat Flux and Storage
The soil heat flux at the surface is calculated by adding the measured flux at a
fixed depth, d, to the energy stored in the layer above the heat flux plates. The
specific heat of the soil and the change in soil temperature,
∆
T
s
, over the output
interval, t, are required to calculate the stored energy.
The heat capacity of the soil is calculated by adding the specific heat of the dry
soil to that of the soil water. The values used for specific heat of dry soil and
water are on a mass basis. The heat capacity of the moist soil is given by:
NOTE
