Re: Gypsum Block Loggers ?

[Rick Allen]

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Dear Mike,

You've probably received responses already describing
the AM400 datalogger from M.K.Hansen.  Another even
more inexpensive solution for monitoring matrix blocks
is to use the Hobo logging system from Onset, although
a little "rigging" is required and the Hobo uses DC
excitation.  I have a report comparing the AM400
and Onset loggers using WaterMark sensors on the web
at the following address.  By and large, the Hobo
units stack up pretty well.  There is also a document
at this same web site that describes how to wire up
the Hobo units for Watermarks.  I have really been
pleased with the AM400 unit for displaying real time
information in the field.

Best regards.  My apologies if this ground has already
been plowed.

http://www.kimberly.uidaho.edu/water/swm/

Rick Allen
Univ. Idaho

--- owner-sowacs@aqua.ccwr.ac.za wrote:
> 
> Gypsum blocks are usually read manually although I'm
> aware of a couple
> options for logging that include radio transmission
> to a receiver/logging
> device (MEA, Adcon).  These are quite expensive.
> 
> I'm looking for a stand alone gypsum block logger
> that can be left in the
> field to record "continuous" data from a small array
> of blocks (say 6),
> which can then be downloaded.  It must be
> inexpensive.
> 
> Some components would be- AC power source; Actuating
> electronics for
> periodic measurements; Resistance or current meter;
> Logger; Multiple input
> ports/channels (nominally 6); Download port;
> 
> Supporting software including calibration of
> resistance to tension for
> appropriate porous media devices would be desirable.
> 
> Do you know of anything that would satisfy these
> requirements.
> 
> Regards,
> 
> Mike Schulz
> Serve-Ag Pty. Ltd
> 
> PO Box 1030, Shepparton, Vic, 3632
> Tel. 03 5825 4783
> Fax. 03 5825 4728
> Mobile.   0408 395 076
> Email: mikeschulz@bigpond.com
>