DEN-1B McFarland Densitometer – Witec AG

Designed for measurement of cell suspension's turbidity in the range of 0.0–6.0 McFarland units (0 – 180×10⁷ cells/ml)

The Densitometer provides the opportunity to measure solution turbidity in a wider range (up to 15.0 McFarland units) however, it is necessary to remember that in this case the standard deviation values increase.

A densitometer is used for measurement of cell concentration (bacterial, yeast cells) during fermentation process, determination of microorganism sensitivity to antibiotics, microorganism identification using various test-systems, for measurement of absorption at the definite wavelength, as well as for quantitative estimation of concentration of colour solution, absorbing green light.

The operation principle is based on measurement of optical density with digital presentation of  results in McFarland units. The unit is calibrated at the factory (for operation with 16 mm diameter glass tubes) and keeps calibration without power supply.

However, if necessary it is possible to calibrate the unit by 2–6 points in 0.0–6.0 McFarland unit range. We recommend to use Biosan standards to ensure full reliability, but it is acceptable to use other commercial as well as self prepared standards (e.g. BaSO4). Possibility to restore factory calibration settings.

Following calibration kits are available on request:

• CKG16 for glass tubes with diameter 16 mm, set of 0.5; 1.0; 2.0; 3.0; 4.0 McFarland Turbidity Standards (latex particles);
• CKG1802 for glass tubes with diameter 18 mm, set of 0.5; 1.0; 2.0; 3.0; 4.0; 5.0 McFarland Turbidity Standards (BaSO₄).
• CKG12 for glass tubes with diameter 12 mm, set of 0.0 (blank); 0.5; 2.0; 3.0 McFarland Turbidity Standards (latex particles).

Included: A-16 adapter for 16 mm tubes.

Powered both from external energy supply and from batteries (AA).