The Calibration of Neutron Moisture Probes

[Carlton Weber]

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I have developed a unique calibration method that I would like to upload for
further comments form sowacs users. the method is currently standard
WaterMan practice, but other may benefit. I am certain that you will find it
useful. the i's and t's may need some dotting and crossing, but this will
come after all comments are in! the method was developed over the past 20
years from my association with civil engineering hydrodensometer guages as
well as neutron probes.
[bruce, please let me know if this is possible for general distribution - it
will be virus free]
[Bruce comments: I have posted an html version on the sowacs website here:
http://www.sowacs.com/sensors/calibration/nmm.htm
Bruce]

regards
carlton weber
development manager
geoquip (pty) ltd
carlton@geoquip.co.za


The Calibration of Neutron Moisture Probes 

The calibration of a neutron probe deals with 4 UNRELATED areas of moisture
content measurement. In many cases, not understanding the underlying
principles of the calibration procedures leads to unscientific guesses and
procedures.
The 4 aspects related to calibration are:
A. The Neutron Probe
B. The Moisture Content Definition
C. The Soil
D. The quality of Water used and Access Tubes used



----- Original Message -----
From: <owner-sowacs@aqua.ccwr.ac.za>
Sent: Tuesday, November 06, 2001 11:00 AM
Subject: NP calibiration query


> NOTE:  To get off this list, send email to majordomo@aqua.ccwr.ac.za
> with the body of the message containing the line:
> unsubscribe sowacs
>
> Dear Sowacsers,
>
> I am a PhD student at the University of Leeds, England. I have been
> researching the ability of ground-penetrating radar (GPR) to detect
> leaks from water supply pipes. At my field site, I have installed 4
> neutron probe access tubes and obtained a suite of data from a study
> leak in order to monitor soil water content changes after leak water is
> introduced into the soil.
>
> The access tubes had to be plastic as metal tubes would interfere with
> the electromagnetic equipment we use at the site. I am seeking advice on
> calibration techniques. I am looking at moisture changes in short time
> period: the leak is relatively high magnitude and so tests only last ~
> 2-4 hours because the ground becomes saturated). Therefore I wondered
> what people thought about the importance of calibration when the
> difference in control and leak data is of primary concern to my work.
>
> Regards
> Ed O'Brien
> ----------------------
> Edward O'Brien
> School of Geography
> University of Leeds
> Leeds LS6 1LP
> Tel: 0113-233-6638
> Fax: 0113-233-3308
> ----------------------
>
>
>
>
>

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