Second2Gray {Luminescence} | R Documentation |
Converting equivalent dose values from seconds (s) to Gray (Gy)
Description
Conversion of absorbed radiation dose in seconds (s) to the SI unit Gray (Gy) including error propagation. Normally used for equivalent dose data.
Usage
Second2Gray(data, dose.rate, error.propagation = "omit")
Arguments
data |
data.frame (required):
input values, structure: data ( |
dose.rate |
RLum.Results, data.frame or numeric (required):
|
error.propagation |
character (with default):
error propagation method used for error calculation ( |
Details
Calculation of De values from seconds (s) to Gray (Gy)
De [Gy] = De [s] * Dose Rate [Gy/s])
Provided calculation error propagation methods for error calculation
(with 'se'
as the standard error and 'DR'
of the dose rate of the beta-source):
(1) omit
(default)
se(De) [Gy] = se(De) [s] * DR [Gy/s]
In this case the standard error of the dose rate of the beta-source is treated as systematic (i.e. non-random), it error propagation is omitted. However, the error must be considered during calculation of the final age. (cf. Aitken, 1985, pp. 242). This approach can be seen as method (2) (gaussian) for the case the (random) standard error of the beta-source calibration is 0. Which particular method is requested depends on the situation and cannot be prescriptive.
(2) gaussian
error propagation
se(De) [Gy] = \sqrt((DR [Gy/s] * se(De) [s])^2 + (De [s] * se(DR) [Gy/s])^2)
Applicable under the assumption that errors of De
and se
are uncorrelated.
(3) absolute
error propagation
se(De) [Gy]= abs(DR [Gy/s] * se(De) [s]) + abs(De [s] * se(DR) [Gy/s])
Applicable under the assumption that errors of De
and se
are correlated.
Value
Returns a data.frame with converted values.
Function version
0.6.0
How to cite
Kreutzer, S., Dietze, M., Fuchs, M.C., 2024. Second2Gray(): Converting equivalent dose values from seconds (s) to Gray (Gy). Function version 0.6.0. In: Kreutzer, S., Burow, C., Dietze, M., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J., Mercier, N., Philippe, A., Riedesel, S., Autzen, M., Mittelstrass, D., Gray, H.J., Galharret, J., 2024. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 0.9.24. https://CRAN.R-project.org/package=Luminescence
Note
If no or a wrong error propagation method is given, the execution of the function is
stopped. Furthermore, if a data.frame
is provided for the dose rate values is has to
be of the same length as the data frame provided with the argument data
Author(s)
Sebastian Kreutzer, Institute of Geography, Heidelberg University (Germany)
Michael Dietze, GFZ Potsdam (Germany)
Margret C. Fuchs, HZDR, Helmholtz-Institute Freiberg for Resource Technology (Germany)
, RLum Developer Team
References
Aitken, M.J., 1985. Thermoluminescence dating. Academic Press.
See Also
Examples
##(A) for known source dose rate at date of measurement
## - load De data from the example data help file
data(ExampleData.DeValues, envir = environment())
## - convert De(s) to De(Gy)
Second2Gray(ExampleData.DeValues$BT998, c(0.0438,0.0019))
##(B) for source dose rate calibration data
## - calculate source dose rate first
dose.rate <- calc_SourceDoseRate(measurement.date = "2012-01-27",
calib.date = "2014-12-19",
calib.dose.rate = 0.0438,
calib.error = 0.0019)
# read example data
data(ExampleData.DeValues, envir = environment())
# apply dose.rate to convert De(s) to De(Gy)
Second2Gray(ExampleData.DeValues$BT998, dose.rate)