Complete packages for 6 or 12 simultaneous measurements. Measurement using OxiTop is based on pressure measurement in a closed system: microorganisms in the sample consume the oxygen and form CO2; the CO2 is absorbed by NaOH, creating a vacuum that can be measured as a mg/l BOD value. The sample volume used regulates the amount of oxygen available for a complete BOD. Measurement ranges of up to 4,000 mg/l can be measured using different volumes. The OxiTop heads (green and yellow for inflow/outflow differentiation) have an AutoTemp function: if the sample temperature is too cold, the start of measurement is automatically delayed by at least 1 hour until a constant temperature has been reached. Apart from the automatic storage of 5 measured values (1 value per day), further measured values can be read at all times during or after the period of 5 days, which permits the tracking of check values or measurements over longer periods.