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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 I will let you know up front that I am a distributor of the Diviner 2000. I have sold the EnviroSCAN and the Diviner 2000 for both research and agricultural uses. I am often asked the same question. In my opinion, you should run both systems concurrently for an adequate period of time to develop a correlation curve. You just can't beat real comparative data. We have some EnviroSCANs and one D2K in the hands of researchers who are comparing them with watermarks, tensiometers, neutron probe, and other capacitance or similar instruments. The best correlation is with the neutron probe, so far. Regards, Dale Agricultural Information Technologies, Inc. 204 E. McKenzie St., Suite E Punta Gorda, FL 33950 (941)505-9197 www.aginfotech.com "You don't miss your water 'till your well runs dry" (Taj Mahal) -----Original Message----- From: owner-sowacs@aqua.ccwr.ac.za [mailto:owner-sowacs@aqua.ccwr.ac.za] Sent: Monday, April 03, 2000 2:59 PM Subject: Volumetric vs Gravimetric 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 I have done some moisture monitoring with Watermarks in the past and now have use of a Diviner 2000 from Sentek. I wish to be able to compare previous years data to current data. One problem I see off the bat is that the Watermarks read in centibars while the D2K reads in mm of water in a profile. I am curious how I might easily convert between the two without doing some gravimetric testing to establish the soil true capacity. Even then, without testing through many matric potentials to establish a proper curve, how could I be sure that each unit was responding to soil moisture in a similar fashion?? Tom Thomson Northwest Agricultural Consulting 1275 Oak Villa Road tomt@teleport.com Dallas, Oregon 97338 Phone/FAX 503-623-0468 "The only difference between a problem and a solution is that everyone understands the solution." Charles Kettering [Why not compare the two sensors directly in a test bed and allow it to dry across the range? Bruce]