Xylem WTW OxiTop-IDS - 5 Operation with Oxitop -IDS Measuring Heads; Measuring; Preparing the Measurement

Multi 3630/3620 IDS Operation with OxiTop
®
-IDS measuring heads
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5 Operation with OxiTop
®
-IDS measuring
heads
5.1 Measuring
5.1.1 Preparing the measurement
Municipal wastewater does not normally contain any toxic or inhibiting sub-
stances. There are enough nutrient salts and suitable microorganisms present.
Under these conditions, BOD determination in the undiluted sample using the
OxiTop
®
-IDS measuring system is possible.
Prior to measuring, carry out the following preparatory activities:
 Keep ready the instruments and accessories required
– OxiTop
®
-IDS measuring heads
– Stirring platform
– Thermostat cabinet/box (BOD standard: temperature 20 °C ± 1 °C)
– Brown sample bottles (bottle volume 510 ml)
– Magnetic stirring rods (1 stirring rod for each sample bottle)
– Magnetic stirring rod remover
– Suitable overflow volumetric flask
– Rubber sleeves
– Nitrification inhibitor ATH (NTH 600)
– Sodium hydroxide tablets (NHP 600)
 Determine the sample volume
(see operating manual of the OxiTop
®
-IDS measuring head)
 Prepare the samples
(see e.g. operating manual of the OxiTop
®
-IDS measuring head or
WTW application reports, chapter "Sample preparation")
Further documents
on BOD
determination
 Operating manual of your OxiTop
®
-IDS measuring head
 WTW application reports (see www.wtw.com)
 DIN EN 1899-2
Water quality - Determination of the biochemical oxygen demand after n
days (BOD) - part 2: Procedure for undiluted samples (ISO 5815:1989, mod-
ified)