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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 Dear Alvaro, We have been using a TRASE BE system (identical to the TRASE 1 but without the screen and the battery) in the field in Thailand for two years without any serious problem. A few recommendations: - make a calibration in your field (theta = f(Ka)) by monitoring the soil water by both TDR and gravimetric samples after an irrigation until the soil becomes dry. The so-called "universal calibration curve" used by the instrument to calculate theta is often quite far from the curve you get by direct measurements. - If you have several waveguides to monitor you may consider buying a multiplexer. Soil moisture equipment provides a multiplexer for 16 to 64 waveguides (for 16 waveguide I must have paid something like 5000 $US). The multiplexer allows you to make measurements as often as every 5 minutes on each waveguide if you use 16 waveguides. This is very useful to follow the dynamics of soil water. If you add solar panels the instrument can work for several days without any monitoring. - You probably know that the data can be downloaded to a PC. I ignore whether other possibilities exist, but I use the Wintrase programme sold by Soilmoisture without problems. If you buy the programme, Soilmoisture equipment will probably suggest you upgrade the RAM of the instrument, because there were communication problems with the first version (yours). I recommand this upgrade. - You can get a good support from Soilmoisture by contacting Herb Fancher <Herb@Soilmoisture.com>. Kind regards, Roland Poss -- Roland Poss, IRD (ex Orstom), Department of Land Development, Division of Soil Analysis, Paholyothin Road, Chatuchak, Bangkok 10900, Thailand tel/fax: (66 2) 579 55 23 e-mail: poss@ksc15.th.com