When operating in the aerobic mode, oxygen – from a supply of pure oxygen – is added in small increments into each respirometer vessel in response to oxygen uptake and carbon dioxide absorption. This mode of operation maintains a constant oxygen concentration in the headspace within the reaction vessel. Oxygen transfer from the headspace to the liquid phase is accomplished by using magnetic stirring units having high mixing rates. When operating in anoxic or anaerobic modes, gases produced by biological reactions flow into an internal storage chamber and are released when a pre-set pressure buildup is detected by a pressure transducer. These incremental volumes are carefully controlled through accurate calibrations established by RSA.
16 and 24-position systems are available. Eight-position systems can be expanded to 16 and 24-position systems with the addition of satellite flow-control modules. All units of a system are connected to a single computer for data acquisition. All standard Pulse-Flow respirometer systems can be operated in aerobic or anaerobic modes without the need to purchase separate control modules or complicated hardware. Anaerobic-only or aerobic-only systems are available on request.
RSA’s PF-4000 is a 4-position respirometer with the same features of our PF-8000 Pulse-Flow respirometer. They are designed specifically to measure oxygen uptake for aerobic biological reactions and gas production from anaerobic and anoxic biological reactions, but in a smaller footprint.
PF-Digital Flow Meters
RSA’s digital flow meters are useful for measuring flow rate from laboratory-scale anaerobic pilot plants. Flow rates range from 2.5 L/hr for the PF-8000F unit (left) to 6.5 L/hr for the PF-1000F unit (right).
WBC Water bath and cover with DMS-8 Stirrer
Water Baths and heater/ coolers or heater-only units are an important part of our respirometer systems. Since the PF-8000 uses pressure differentials to measure oxygen uptake or gas production, the test reactors should be operated within plus or minus 1°C to minimize errors due to temperature fluctuation. We can quote water baths and heater/coolers or heater-only units for your respirometer package. If you have an incubator or temperature control room you may eliminate the need of ordering temperature control from RSA.
The DMS-4 and DMS-8 stirring bases (DMS-8 pictured above) are designed and constructed with the following features:
– Individual or simultaneous speed control
– Stirring speeds up to 1,500 rpm
– Minimal heat generation
– Stainless steel cabinets to eliminate corrosion
– Welded joints to eliminate water damage.