Electronic Data Collection and Analysis System
Yin Foo, Des; Foley, Margaret
E-Publications; PublicationNT; E-Books; Report ; 39/1992
1992-08-01
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Date:1992-08
English
Power and Water Authority
Darwin
Report ; 39/1992
application/pdf.
Check within Publication or with content Publisher.
https://hdl.handle.net/10070/229024
https://hdl.handle.net/10070/673447
Technical Report WRD92039 Viewed at 15:07:17 on 29/07/2010 Page 34 of 192. Resul ts so far indicate the l-lesdata 10m system to be accur<:l.'ce to ;"i thin 1. 2 %FS at a depth of 140 %FS and the Hindata 20m vented system to be accurate to within 0.14 %FS at a depth of 150 %FS. These figures were obtained from preliminary testing of the above have not been validated. It mentioned systems and as yet should also be noted that out-of-ranging is generally not desired and some loggers may activate self protection measures to avoid potential damage due to this practice. 3.2.3.4 Drawdown Test 'Phese tests were performed in the same .. 'ell as the static tests, with the water level varied by pumping and recharging. The main well is evacuated by pumping from an adjacent well connected to it at the bottom. The manual readings were taken using a "Tape and Float system". Two people were needed to take the manual readings - one monitoring time and the other readin<;J the float tape (the float tape was held while the readin<;J was taken). The timing of the readings could reasonably be taken wi th readings from approximately 10rnrn. to be accurate to 'ilithin one second and the tape and float system accurate to An accuracy of approximately 20rnrn should therefore be attained from the manual readings if the drawdown rate is 10rnrn per second. Repeat tests were carried out for each system to validate the results. The float measuring system was checked using a transducer tapE!. The systems were recalibrated between tests. The errors quoted in Table 3.2 are differences between logged and manual readings. The sources of error may be identified mainly from non-linearity hysteresis effects. This is indicated in where loop type responses are apparent. used for recalibration of data if the deviation 1S considered significant. of response Figures 3.2 to and 3.5 such curves may be magnitude of the Deviation from the "theoretical" response is generally greatest between the