counts2eps: Convert oscillation frequency output/Counts from SMT100...

In TillF/FDR2soilmoisture: Processing data of FDR-measurements to obtain soil moisture

Convert oscillation frequency output/Counts from SMT100 sensors into permittivity and v.v

Description

Convert oscillation frequency output from SMT100 sensors into permittivity and v.v using an empirical model.

Usage

counts2eps(counts, alpha=-0.1305, beta=0.2549, gamma=1.8342)
eps2counts(perm, alpha=-0.1305, beta=0.2549, gamma=1.8342)

Arguments

counts	counts/oscillation frequency measured by a SMT100 sensor [-]
perm	apparent dielectric permittivity [-]
alpha, beta, gamma	Calibration parameters, see Details

Details

The following empirical model is used from Bogena et all, 2017:

\epsilon= \gamma + \frac{1}{\alpha+\frac{\beta}{(18000-counts)/5000}}

The function uses as default average parameters for alpha, beta and gamma (table 2, Bogena et all, 2017). Nevertheless, since each sensor is individually calibrated those should be set individually too.

Value

Permittivity value (epsilon) [-] or sensor counts [-].

Author(s)

Jakob Terschluesen

References

Bogena, H.R.; Huisman, J.A.; Schilling, B.; Weuthen, A.; Vereecken, H. Effective Calibration of Low-Cost Soil Water Content Sensors. Sensors 2017, 17, 208. https://doi.org/10.3390/s17010208

Examples

#random counts
counts2eps(10000)

#eps for air
eps2counts(1.00059)

#individual set of parameters:
counts2eps(10000, alpha=-0.1306256,beta=0.254624, gamma= 1.834865)
eps2counts(1.00059, alpha=-0.1306256,beta=0.254624, gamma= 1.834865)

TillF/FDR2soilmoisture documentation built on Dec. 6, 2024, 9:30 a.m.