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TYPE OF ANALYSIS |
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PRICE |
(2012) |
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CAN$ |
US$ |
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Pb-210 in dry sediments (no modelling or plotting) |
$ 77.50 |
$ 77.50 |
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Pb-210 in dry sediments
(with modelling & plotting) |
$ 90.75 |
$ 90.75 |
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Pb-210 in wet sediments (with bulk density, but no modelling or plotting) |
$ 87.50 |
$ 87.50 |
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Pb-210 in wet sediments (with bulk density, modelling & plotting) |
$ 100.00 |
$ 100.00 |
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Ra-226 in dry sediments by radon emanation |
$ 116.50 |
$ 116.50 |
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Ra-226 in wet sediments by radon emanation |
$ 122.50 |
$ 122.50 |
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Cs-137 in dry sediments (22 hr. on 3x3 NaI (Tl)) |
$ 77.75 |
$ 77.75 |
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Cs-137 in wet sediments (as above) & drying |
$ 88.00 |
$ 88.00 |
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Cs-137 extra day of counting on 3x3 NaI (Tl) |
$ 64.50 |
$ 64.50 |
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Cs-137 in dry sediments (22 hr. on HP Ge) |
$ 116.50 |
$ 116.50 |
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Cs-137 in wet sediments (as above) & drying |
$ 126.75 |
$ 126.75 |
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Cs-137 + Be-7
in dry sediments |
$ 141.00 |
$ 141.00 |
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Cs-137 + Be-7
in wet sediments |
$151.00 |
$151.00 |
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Set up charge for Be-7 (calibration) |
$307.00 |
$307.00 |
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The above radioisotopes (except Ra-226) are usually measured in 10 to 20 sections of a sediment core to determine the rate of sediment accumulation in a water body. The age of the sediment from a particular depth in the sediment column can then be inferred.
The Pb-210 results will normally be modelled to obtain the best fit of the data, where possible. The CRS model and/or the slope regression model will be applied. A plot of Pb-210 activity vs. cumulative dry weight (g/cm2) is supplied with the model results.
The Cs-137 data will be interpreted on the basis of the 1959 and 1963 major input peaks of the isotope. Modelling is usually not attempted because our experience indicates that Cs-137 diffuses fairly rapidly through many sediments. A plot of Cs-137 activity vs. depth (cm) is supplied with the results.
Unless special arrangements have been made, the minimum number of samples accepted is 10 at any one time. Turnaround time depends upon the number of samples submitted and the number of samples in the queue. Times are typically 1-3 months. Please ask for an estimated completion date when submitting samples. If fast service is required, we may be able to count selected core sections to obtain a preliminary rough approximation of sediment accumulation rates.
For Pb-210 modelling purposes we require the dry bulk density of the sediment in each section (= the dry weight per wet cc). If samples are submitted wet, we determine this value ourselves; if the samples are submitted dry, we request that this information be made available to us prior to modelling the Pb-210 results.
Ra-226 measurements are made, usually 2 - 3
per Pb-210 core, to estimate background Pb-210 activity when a core is not long
enough to have reached constant activity in the deepest sections.
For additional
information, contact Dr. Robert Flett at flett@flettresearch.ca
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Phone/Fax : |
(204) 667-2505 |
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Mailing Address: |
Flett Research Ltd. |
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440 DeSalaberry Ave. |
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Winnipeg, Manitoba, Canada |
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R2L 0Y7 |
Return to the Flett Research Home Page.
Last Updated January 1, 2012 Flett Research Ltd. E-Mail: flett@flettresearch.ca