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 52 of 192. A test was conducted over a 2 month period using the J:.1indata. barometric probe (serial No. 120222) and the 3500 Series logger. The probe was set up in an air-conditioned office, and logged at least every hour. The Bureau of Meteorology ad'Jised that Barometric pressure changes inside the office WOLld be very close to those recorded in their (also air-cond:.tioned) recording site, which is within 10 km of this office. Figure 3.,.2 is a plot of Barometric pressure with Time, showing the recalibrated logged data, and the Bureau of Meteorology data for the period 17/9 to 21/9/91. This is typical of the data recorded over the two month period. a The logger was originally calibrated for this probe Druck Pressure Instrument (see section 3.2.3). using This calibration was performed using the "metres of ("/hich assumes ~later density of 1000 kg/m3) recalibration using 'DATJ:.IAN' (as per example in probably for the reasons outlined in section water" scale and required Appendix D), 3.2.3 above {pressure fluctuations through the tube used to connect to the transducer). After recalibration, the maximum inaccuracy found in the 37 readings compared was equivalent to 4mm (O.13%FS) of water. 3.3.6.2 Comments The syste:u performed accurately and reliably over the 2 month period. The necessity to take two measurements and <ttmospheric pressure) to find one parameter (water will likely produce some additional error to the data. (water level) 'l'he Bureau of Meteorology has reported some problems with Blectronically logged barometric pressure data. For example, instar,taneous readings can be affected by wind gusting. A contai.ner for the probe must include vents to avoid pressurisation, while providing reasonable temperature stabi.li ty .