McNab Model DLB Dual-Angle Haze Laboratory Instrument

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The DLB provides an accurate measurement of large and small haze particles in one instrument. Haze has been a classical measurement for beer quality--usually at one of two scatter angles. However, now with the addition of the second scatter angle, the 0.1 to 1 micron protein component is measure along with the larger yeast and DE component. This new arrangement supplies a profile of particle size distribution.


Top: 90 Scatter
Middle: Forward Scatter
Bottom: Bath Temperature

Sample Chamber:

  • Optical quality sample bottle - capped or open
  • Temperature control sample bath
  • Operate below 0 C
  • 4-Head design
  • Automatic Centering of Bottle or Cuvette
  • Automatic Rotation of Bottle or Cuvette (As Accessory)


  • Matches In-Pipe Haze Analyzers
  • Measures Large & Small Particles
  • Hermetically Sealed Optics
  • Automatic Range Selection

Use for:

  • Beer, Wort, Wine, Juice
  • Shelf-Life Analysis
  • Colloidal Stability Predictions
  • Microbiological Purity Analysis
  • Filtration Efficiency Analysis

The yeast or particle is suspended in the chamber and light scatters off the particles and simultaneously is read at three different angles--forward scatter, 90, and direct. The lower "gain" of the forward scatter effectively precludes the measurement of particles smaller than 1 micron; whereas the 0.5 micron protein suspended particles as well as the yeast size particles are seen by the 90 scatter angle. The comparison of the two angles will highlight what otherwise would not be identified (the 0.1) to 1 micron protein particle).

This unit is manufactured at McNab, whose analyzers are well-known. One of the design goals was to have a laboratory DLB "match" the optics of the across-the pipe instruments.

This dual-angle instrument is a quad-head design - one head for the light source, one for the background suppression, one for the 90 and one for the forward scatter signal.  This combined design with common optics (specifically the illumination) eliminates the distortion error otherwise occurring when comparing with two different sets of instruments.  This optical matching facilitates the user's ability to calculate the shelf life of his sample.


Model DLB
Principle of Measurement: 2-angle view geometry (forward and 90) optical scatter, ratio via a common reference signal, water-based.

0-2.00, 0-20.00 EBC

0-2.00, 0-20.00 FTU

0-2.00, 0-20.00 NTU

0-20.00, 0-200.0 PPM as SiO2 Custom range/units



+/- 0.04 or 2% on 0 - 2 scale.

+/- 0.40 or 2% on 0 - 20 scale

+/- 4.0 on 0 - 200 scale


+/- 0.03 or 2% of reading whichever is greater; on standard range, light, particle, bottle, and calibration method.

Standard Deviation (typ.): Automatic (hue and intensity). When over range, "Status 2" indicator flashes.
Color Compensation: Automatic (hue and intensity). When over range, "Status 2" indicator flashes.
Measurement Type:

1. Classic scatter instrument (typ)

2. Electronically enhanced for improved particle size suppression.

Outputs (Optional): 0 to 1 Ma, RS-232
Optical Lamp: 370 - 2800 nm, tungsten filter adjusted to green, white, red, or NIR to suit customer specifications.
Measuring Chamber: SS 316L, glass optics
Lamp Life: 12 years (assuming 8 hours continuous daily use).
Sample Cell:

Closed Style Optical Quality: 

2 - 1/4" Dia. x 4?1/2", 200 ml size 

Open Style Optical Quality: 

62 mm Dia. x 150 mm 250 ml size. 

Contact factory for other sizes.

Operating Temperature: 22 - 150F (-5 - 50C). Use additives when operating below freezing point of water.
Power Requirements: 115 or 220 VAC, 100 watts, 50 to 60Hz
Correlation (typ): 0.99 to DSB, RS, & HSB analyzers
Calibrating Span Fluid: Formazin Primary Standard or PPM as SiO2
Calibrating Zero Water: Ultra-filtered laboratory grade (if applicable) better than 0.1 NTU or 1/10th of Span value.
Circulating Water: Supplied (or use supermarket bottled water).
Light Source: Polychromatic: (400 - 800 nm white light, 370 - 2800 Tungsten) or quasimonochromatic: red, Green, NIR, MEBAK
Sensors: Dual ratio photodiode sensors
Units: ASBC, EBC, NTU, PPM or custom
Ranges (typical): 0 to 10 (20) EBC
0 to l000 ASBC
0 to 200 PPM/DE
Automatic Switching
Resolution: 1 part in 2000
Bath: Water filled for cooling with chamber temperature measurement.
Weight: 50 lbs.(22.6 kg)
Dimensions: 10"h x 16" w x 25" d (25 x 40 x 63cm) in stainless steel cabinet (316)
Measuring Container:  Chamber holder ID to match customer sample bottle
Display: Three bright 1/2 high digital LED displays.
Operation: One-touch button control
Color Rejection: Electronics Ratio Method
Adjustments: Zero and span
Fog Alarm: Condensation RH chemical indicator and electronics flashing alarm
Water Services: Rear inlet & output ports. Accepts 3/8" (9.5 mm) inside diameter tubes.
Circuit: Computer enhanced
Accessories: On-line adapter sample kit
Rings for non-standard bottle
Sample various wet standards for calibration purposes
4000 NTU calibration standard
Sample cell open or closed
Rotating sample chamber
Calibration plot
Meets CE requirements

383-2 East 29th Street | Buena Vista, VA | USA 24416-1293

540.261.1045 voice | 540.261.1268 fax |

Copyright 1999 - 2010  McNab, Inc. All Rights Reserved.  Last modified: 08.12.2010

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