An automatic system for recording evaporation from ET gages

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A low cost automatic data acquisition system was developed for modified Bellani plate atmometers or ET gages (ETGs) that consisted of a float and pulley system with an optical encoder and a low cost data logger that detected switch closures. The system cost was approximately $200 to retro-fit an existing ETG. Laboratory testing of this system indicated that errors were in the range of errors reported for lysimeter data versus Penman Montieth ET o estimates and within the range of errors reported for ETGs compared to ET o estimates. The float and pulley system performed better under conditions of 4-6 mm ET during an increment (i.e. day) because errors associated with manual reading of the site tube were minimized. Future work on the system should include field testing.

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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