Electronic Data Collection and Analysis System
Yin Foo, Des; Foley, Margaret
E-Publications; PublicationNT; E-Books; Report ; 39/1992
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Power and Water Authority
Report ; 39/1992
Check within Publication or with content Publisher.
Technical Report WRD92039 Viewed at 15:07:17 on 29/07/2010 Page 42 of 192. drawdown was compared to manual readings taken at intervals durin<;i the test:. At this stage, the type of pump used may be considered to represent turbine notvlithstanding the possibility of any effects from the pump motor downhole . pumps in general, electrical interference . !'. 7 minute section of both logged data sets is shown in Figure 3.8 as a "screen dump" fron the "datman" screen. The overall accuracies of both systems were comparable, with both having approximately 95% of readings within 50mm of the manual readings. In Figure 3.8, the Mindata output shows some variation of the type encountered in bores pumped with a Helical Rotor pump, but to a much smaller extent. The maximum amplitude of the vibrations found was 35mm and the period shown is around 16 seconds. 18.104.22.168 Comments Examination of the graphs produced from the above tests led to the following conclusions : (i) A hel ical rotor pump (eg. MONO) driven by a diesel TEotor lS unsuitable for use in a bore where "Jater level is to be logged using a system which takes instantaneous readings unless the output is conditioned. (ii) with helical rotor pumps, the size of the data scatter in logged head is dependent on the pump shaft speed (\vorst at pump speeds below the specified efficency range) and, to a lesser extent, on the pump motor speed (worst at very low engine speeds). (iii) The Wesdata logging method (measuring the probe's frequency output over 1 second) largely overcomes the problem at least in situations where the instantaneously logged readings are showing a variation of up to 300mm. ~~he Wesdata system however is currently limited by size