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.

Specifications

Dimensions	43 x 54 x 41 cm, 17 x 21 x 16 in. (w x h x d)
Weight	20 kg, 44 lb.
Voltage	120 and 240 V AC
Frequency	50 to 60 Hz
Consumption	20 VA
Ambient temperature	+5 to +40 °C
Storage temperature	-40 to +70 °C
Burette	Metrohm 765 Dosimat
Exchange unit	1, 5, 10, 20 or 50 ml
Accuracy	Absolute 0.3 %, Repeated 0.1 %
Photometer	Alternating light photometer operating with two wavelengths, 15 Bit ADC

System Requirements

MS-DOS Software

DO Analyser	All O2 plus and DOA versions
System	IBM® PC/XT/AT or true compatible
Operating system	MS-DOS® 3.10 or higher
Processor	Minimum 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 Coprocessor Mouse with Microsoft® compatible mouse driver

Windows Software

	Minimum	Recommended
DO Analyser	DOA version 2.2
System	x86 compatible, 400 MHz	800 MHz
Operating system	Microsoft® Windows® 98, 98 SE, ME, NT 4 SP6a, 2000 SP2, XP	2000 SP4, XP SP2
Software	Microsoft® DAO 3.6 (Data Access Objects) Microsoft® Jet Engine Version 4.0
Memory	64 MB	128 MB (256 MB with Windows XP)
Free disk space	10 MB	100 MB
Screen resolution	800 x 600	1024 x 768
Serial port	One 8250 based RS 232 C interface

Additional Information

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