SiS Sensoren Instrumente Systeme GmbH

DOA Dissolved Oxygen Analyser

DO Analyser Photo The DO Analyser is an easy to use, PC controlled instrument for the determination of dissolved oxygen in aqueous solutions according to the method developed by L.W. Winkler in 1888.

This chemical titration method is the standard for determination of oxygen in samples, even in modern times, because all in situ systems are less accurate. The method needs well educated and experienced personnel but nevertheless produces individual results because the titration endpoint is determined by eye. Qualified personnel get very reproducible results which have an individual offset. This offset limits the accuracy to a value considerably beyond the principle accuracy limits of the method. The current trend towards increasing international co-operation and participation in joint programmes brings with it the greater need for measurement comparability.

The DO Analyser fills this gap for it works at the accuracy limit of the method, does not need experienced and qualified personnel and potentially gives error free, well-documented results on machine readable media. The acquisition, and the chemical pre-treatment, of the samples prior to titration are left unchanged but the determination of oxygen by titration of the iodine with thiosulphate solution is automated.

The system consists of a robust transportable box, the software and an interface cable from the box to PC. Within the box is a motor burette, a stand with a stirrer for the sample flask, the photometer and the interface box providing, via RS 232 serial link, communication for photometer and burette with the computer.


Dimensions43 x 54 x 41 cm, 17 x 21 x 16 in. (w x h x d)
Weight20 kg, 44 lb.
Voltage120 and 240 V AC
Frequency50 to 60 Hz
Consumption20 VA
Ambient temperature+5 to +40 °C
Storage temperature-40 to +70 °C
BuretteMetrohm 765 Dosimat
Exchange unit1, 5, 10, 20 or 50 ml
AccuracyAbsolute 0.3 %, Repeated 0.1 %
PhotometerAlternating light photometer operating with two wavelengths, 15 Bit ADC

System Requirements

MS-DOS Software

DO AnalyserAll O2 plus and DOA versions
System IBM® PC/XT/AT or true compatible
Operating system MS-DOS® 3.10 or higher
ProcessorMinimum 8088, preferred 80286
Memory 640 KB (minimum 448 KB free memory)
Drives Any with 1 MB free disk space; Hard disk preferred
Video card MDA (Hercules® monochrome), CGA, EGA, VGA or MCGA
Serial ports One 8250 based RS 232 C interface (two for use of serial mouse)
Optional One Centronics® interface for Epson®-FX compatible line printer
Mouse with Microsoft® compatible mouse driver

Windows Software

DO AnalyserDOA version 2.2 
System x86 compatible, 400 MHz 800 MHz
Operating system Microsoft® Windows® 98, 98 SE, ME, NT 4 SP6a, 2000 SP2, XP, Vista, 7 2000 SP4, XP SP2, Vista, 7
Software Microsoft® DAO 3.6 (Data Access Objects)
Microsoft® Jet Engine Version 4.0
Memory 64 MB 256 MB (512 MB with Windows XP, 1024 MB with Vista and 7)
Free disk space 10 MB 100 MB
Screen resolution 800 x 600 1024 x 768
Serial port One RS 232 C interface, optional via USB-to-Serial converter  

Additional Information

SiS GmbH reserves the right to change specifications without prior notice.

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