Model No. 026-301 The principal difference in this simplified model and the automated respirometer is that the use of oxygen must be manually read in the Simplified Respirometer. This model will perform most of the same tests, but requires more labor. It was developed primarily for use by smaller wastewater treatment plants with limited budgets, and where a great many tests will not be run on a regular basis. It is also ideal for high school and college laboratories. A water bath for temperature control is not a standard feature, but can be supplied upon request. This is a very simple, rugged instrument.
FEATURES Aerobic or anaerobic test capability No contact between sensor and sample tested No limit on ambient air supplied to test chambers Vigorous airlift mixing of liquids prevents settling Fine bubble diffusion ensures excellent oxygen transfer Modular construction for easy cleaning, replacement of parts OPERATION PRINCIPLE Each measuring device utilizes a combination of sample chamber, carbon dioxide scrubber, volume manometer and air pump. The air pump provides continuous air circulation through the sample chamber and the scrubber. The entire air system is closed to the atmosphere. As the specimen in the chamber utilizes oxygen and generates carbon dioxide, the carbon dioxide is immediately removed by the caustic solution in the scrubber. The volume of carbon dioxide produced is, therefore, not present to balance the volume of oxygen utilized, and there is a net loss of gas volume equal to the volume of oxygen utilized. The change of gas volume is sensed by the gas volume manometer. It can also be used to measure the volume of gas produced, as in anaerobic processes. BASIC COMPONENTS Sample Chamber The instrument has a standard two-liter cylindrical chamber, but other sizes and shapes can also be provided. On the removable top of the sample chamber is a fill tube closed with a threaded plug.The plug is fitted with a syringe connector for calibration.Sample Chambers are disassembled to clean. With liquid samples the chamber utilizes an
airlift pump to aerate and mix the sample.Air is distributed at the base of the airlift column through a fine
bubble diffuser. Solid samples are
usually placed on a set of porous, acrylic stages and air flows continuously through the solid samples on the stages.
CO2 Scrubber...The CO2 Scrubber is an acrylic tubular chamber containing 400 ml of potassium hydroxide solution. The purpose of the
scrubber is to remove the volume of CO2 which is generated in
metabolism so it will not interfere with the volume of oxygen used in
respiration.A color indicator is added
to the KOH solution that gradually fades when the CO2 absorption capacity is
spent and must be replaced with new solution.The scrubber can be removed from the base to drain.
Air Pump...The Air Pump continuously forces air through the fine bubble diffuser in the sample chamber and CO2 scrubber at a
rate of 3 liters per minute.The combination of fine bubble diffuser and airlift column creates a mixing
reaction in the sample chamber to ensure good contact of organic matter, microorganisms and oxygen.
Model No............................................026-301 Single
(2-Liter): Inside, 4"D x 13"H Other sizes available:
- Inside 2 1/2"D x 13"H
Net Weight ................................25 pounds
Shipping Weight........................30 pounds
Air Pump..............Pumping rate: 3 L/min at 1 ft. Head
Air Capacities...............................1000 ml without
Range of total oxygen demand.........................not
Power Source...100-240V AC 50-60 Hz Output 12V DC 60 Watts
Precision.................+2% as measured with sodium sulfite
Warranty...Fully warranted against manufacturer’s defects
for Eighteen months
Patent...Arthur Respirometers are patented under one or all
of the following patents: 3 ,348.409; 3,740,320; 4,314,969; or 4,650,767. Other
patents are pending.
Toll Free in USA & Canada 1-800-328-7518 Tel: 920-922-6970 Fax: 920-922-1085