Campbell Scientific CR9000X Measurement and Control System - Manual (Page 322)

Section 8. Processing and Math Instructions
Parameter
& Data Type Enter STDDEVSPA PARAMETERS
Dest
Variable or
Array
The variable in which to store the results of the instruction.
Swath
Constant
The number of values of the array over which to perform the specified operation.
Source
Array
The name of the variable array that is the input for the instruction.
SatVP (Dest, Temp)
SatVP calculates saturation vapor pressure (over water Svpw) in kilopascals
from the air temperature (
°C) and places it in the destination variable.
Syntax
SatVP( Dest, Temp, )
Remarks
The algorithm for obtaining Svpw from air temperature ( °C) is taken from:
Lowe, Paul R.: 1977, “An approximating polynomial for computation of
saturation vapor pressure,” J. Appl. Meteor, 16, 100-103.
Saturation vapor pressure over ice (Svpi) in kilopascals for a 0 °C to -50°C
range can be obtained using SatVP and the relationship
Svpi = -.00486 + .85471 Svp + .2441 Svp 2
where Svpw is derived by SatVP. This relationship was derived by Campbell
Scientific from the equations for the Svpw and the Svpi given in Lowe’s paper.
Parameter
& Data Type Enter SATVP PARAMETERS
Dest Variable in which to store saturation vapor pressure (kPa).
Temp Variable containing air temperature ( °C).
StrainCalc(Dest, Reps, BrConfig, Source, Zero, GF, v)
Converts the output of a bridge measurement instruction to microstrain.
Syntax
StrainCalc (Dest, Reps, BrConfig, Source, Zero, GF, v)
Remarks
Calculates microstrain,
μ∈, from the appropriate formula for the bridge
configuration. All are electrically full bridges , the quarter bridge, half bridge
and full bridge strain gages refer to the number of active elements (i.e., strain
gages), 1,2, or 4 respectively.
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