FEATURES OF THE ARTHUR
 SIMPLIFIED RESPIROMETER

        Model  No. 026-301 
Simplified Respirometer
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.  

SPECIFICATIONS

Model No............................................026-301 Single

    .  Sample Chamber (2-Liter): Inside, 4"D x 13"H
        Other sizes available:

    .  CO2 Scrubber - 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 venting

    Range of total oxygen demand.........................not limited

    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








 

 




 

 

 
 
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