RE: remote sensor to sense thin soil surface layer

[Kees van den Bos]

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Dear Sowacsers,

for all people interested in microwave techniques:

I have once encountered a commercial manufacturer of microwave systems for 
soil humidity measurements. These observations were made sometimes from an 
airplane to verify satellite observations, and sometimes from a vehicle to 
monitor surface conditions of roads during fog development /rain/icing 
development. The company name is Attex (or Attech; russian x is our ch). 
The company is Moskow (Russia) based. They are represented in Europe by 
Kipp & Zonen. http://www.kippzonen.com  Pricing of microwave systems anyway 
will be high (more than USD 15.000 per wavelength) and probably you will 
need more than one wavelength. Main benefit:  you can work in a completely 
passive way (no source, just radiometers),and indeed the microwave 
radiation can cover the first couple of millimeters to centimeters of soil 
surface.
Some people believe that microwave radiometry will develop into more common 
technology and that volume will be the key to price reduction. This I 
believe would be very good news to the soil moisture monitoring community.

Best regards,

Kees van den Bos

Hukseflux Thermal Sensors
e-mail: info@hukseflux.com
for news: http://www.hukseflux.com/whatis.htm
P.O. Box 2816
2601CV Delft, The Netherlands
Fax: 31-15-2574949
further information: http://www.hukseflux.com/ordering.htm

-----Oorspronkelijk bericht-----
Van:	owner-sowacs@aqua.ccwr.ac.za [SMTP:owner-sowacs@aqua.ccwr.ac.za]
Verzonden:	21 April 2001 13:09
Onderwerp:	Re: remote sensor to sense thin soil surface layer

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Hello,

If it helps about sensor to measure 1 mm deep water content: Microwave 
sensors
are probably expensive. Since it is only 1 mm deep, may be a Werner or
Schlumberger array configuration electrode about 1 mm in size could be 
enough.
Excitation should be AC in order to overcome polarization effects. I don't
know any company that supply above described sensor.

Best regards,

Josep M. Torrents



owner-sowacs@aqua.ccwr.ac.za wrote:

> 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 subscribers,
>
> I'm looking for a sensor to measure water content (or potential) at the
> upper 1 mm of the soil surface. The sensor should be non-destructive and
> should preferably measure as a stand alone unit. The sensor is meant for
> laboratory measurements (wind tunnel). I was thinking at a microwave
> sensor or something similar. Does anyone of you have some experience
> with such a sensor or knows a company that could help me? Your help
> would be truly appreciated.
>
> Best regards,
>
> Wim
>
> [Bruce comments:
> This area of sensing has not yet been covered by sowacs, so I am hoping 
we
> can collect and compile some good information from replies.Thanks for the
> question, Wim and please pass on any useful info you may recieve directly
> as well. Bruce]
>
> --
> ===========================================
> Wim Cornelis
> Department of Soil Management and Soil Care
> University of Ghent
> Coupure links 653
> B-9000 Gent
> Belgium
> tel.: +32 (0)9 264 60 40
> fax: +32 (0)9 264 62 47
> e-mail: wim.cornelis@rug.ac.be
> http://soilman.rug.ac.be
> ===========================================