Portable turbidity meter DEN-1

monitoring

Overview
Densitometer DEN-1 is designed for rapid measurement of cell suspension turbidity expressed in McFarland units (McF). Standard measurement range is 0.00–6.00 McF with reliable accuracy; extended measurements up to 15.00 McF are possible with increased standard deviation. The instrument is factory-calibrated for 16 mm glass tubes and retains calibration without power supply.

Applications

• Monitoring cell concentration during fermentation and culture processes (bacterial and yeast cells)
• Determination of microorganism sensitivity to antibiotics and support for identification tests
• Measurement of absorbance at a defined wavelength for coloured solutions absorbing green light
• Routine laboratory turbidity control and quality checks in microbiology workflows

Operation and calibration
The DEN-1 measures optical density and displays results digitally in McFarland units. Factory calibration is provided for use with 16 mm glass tubes; calibration is retained when the device is powered off. If required, the unit can be calibrated using 2–6 calibration points within the 0.0–6.0 McF range. Factory calibration can be restored at any time. Biosan calibration standards are recommended for traceable results; alternative commercial or self-prepared standards (e.g. BaSO4) are acceptable.

Available calibration kits

• CKG16 for 16 mm glass tubes: 0.5; 1.0; 2.0; 3.0; 4.0 McFarland Turbidity Standards (latex particles). Cat.Nr.: BS-050102-BK
• Calibration kit for 18 mm glass tubes: 0.5; 1.0; 2.0; 3.0; 4.0; 5.0 McFarland Turbidity Standards (BaSO4). Cat.Nr.: 70900
• Calibration kit for 12 mm glass tubes: 0.0 (blank); 0.5; 2.0; 3.0 McFarland Turbidity Standards (latex particles). Cat.Nr.: 21255

Product versions

• DEN-1 mains powered (external power supply)
• DEN-1B mains and battery powered (AA batteries)

Technical specifications

• Measurement range: 0.00–15.00 McF
• Resolution: 0.01 McF
• Light source: LED
• Measurement wavelength (λ): 565 ±15 nm
• Accuracy (0.0–6.0 McF): ±3%
• Measurement time: 1 s
• Sample volume: ≥ 2 ml
• Tube external diameter: 12 mm, 16 mm (with A-12, A-16 adapter) or 18 mm (without adapter)
• Factory calibration restore: yes
• Display: LCD
• Overall dimensions (W×D×H): 165 × 115 × 75 mm
• Weight: 0.7 kg
• Input current / power consumption: 12 V, 7 mA / 0.1 W
• External power supply: AC 100–240 V, 50/60 Hz input; DC 12 V output
• Standard set: external power supply, A-16 adapter