Firma:              Biotest

Modell:            RCS Standard

Kommentar:   Dokumente engl.

Applications

The Standard RCS Air Sampler is a convenient Instrument for measuring the concentration of airborne microorganisms.

Possible investigations include:

•            the general microbiological quality of ambient air

•            the efficiency of air treatment and air cleaning equipment

•            the effectiveness of decontamination measures

The Instrument can be used in the following areas:

•            food and beverage industries

•            packaging industry

•            pharmaceutical and medical device industries

.            cosmetics industry

•            hospitals

•            public health offices

•            industrial hygiene

•            animal husbandry

Principle of Operation

The Biotest RCS Air Sampler operates on the impaction principle. The function of the air sampler is to deposit airborne microorganisms quantitatively onto a culture medium.

The air under examination is drawn into the sampler from a distance of at least 40 cm by means of an impeller. The air flow enters the impeller drum concentrically and in a conical form, is set in rotation, and the particles contained in the air are impacted by centrifugal force onto an agar medium. The air then leaves the drum in a spiral form around the outside of the tone of air entering the sampler. After sampling, the agar strip is incubated and the colonies are counted.

Due to its principle of operation and the geometric properties of the impeller system, the RCS Air Sampler exhibits a special volume characteristic. lt is therefore necessary to differentiate between the sampling volume (= total volume sampled) and the separation volume (= relevant volume for particle separation).

Sampling Volume

The air flow enters the impeller drum concentrically with a diameter of 2a and at velocity C _ax , is deflected by the impeller blade and fed over the agar strip. The air flow exists via an annular gap with width b. The total sampling volume(v) can be deter­mined through a point by point measure­ment of the velocity and angle of flow over the radius r and subsequent mathematical evaluation. This sampling volume is 280 I/ min at the Instrument speed of 4096 rpm. This sampling volume is the basic parame­ter for calculating the separation volume.

Separation Volume

The particles in the air flow between the impeller blade and agar surface are accelerated by centrifugal force and impacted onto the agar surface. However, only part of the total sampling volume is relevant for particle separation. This separation volume can be determined mathematically, whereby the height of the impeller drum is the most important parameter. This height (I _min ) can be calculated for the separation of all particles contained in the total sampling volume. The basis for this is the resolution of a differential equa­tion which describes the spiral flight path of the particles under the influence of the air flow velocity, the direction of flow and the centrifugal force that arises.

For a relevant particle diameter of 4 µm this produces a height (I _min ) of 14 cm. However, since only 2 cm of 14 cm are available in the impeller drum as the separating height, separation is not effected from the total sampling volume but only from 1/7 of this.

Thus separation volume for the Instrument is 40 liters per minute based on an average particle diameter of 4 µm.

Technical Data

Sampling principle

The Biotest Standard RCS Air Sampler operates on the principle of impaction, whereby the air stream enters the unit at the front of the instrument and the airborne microorganisms are separated out onto the agar strip by centrifugal force.

Measurement range:

Min. 20 liters, max. 320 liters

Air flow rate (Separation Volume):

40 l/min

Memory locations:

5 memory locations for 0.5, 1, 2, 4 and 8 minutes, in ascending order.

Motor speed:

4096 min ¹ (rpm)

Instrument deviation:

± 2 %

Power supply:

4x1.5 . Volt monocells (alkaline D cells, type LR20) or mains adapter 230 Volt /110 Volt.

Electrical power:

3 W

Materials:

•            Housing: chromium plated brass

•            Keypad: polyester; resistant to common disinfection agents

•            Impeller Made: aluminum•autoclavable

•            Impeller drum: chromium plated brass; autoclavable

Weight:

approx 1,300 g (2.9 Ibs) with batteries

Miscellaneous:

•            Screw thread connection for floor plate

•            Infrared remote control sensor

•            Keypad with pressure keys and LED indicators

•            LED indicator for battery voltage

•            Protection cap p made from POM; autoclavable

•            Connection for mains adapter

•            CE Mark