CarboQC

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CarboQC

• Lab and at-line Beverage Carbonation Meter

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Contents of this presentation

• Basics of CO2 analysis
• Multiple Volume Expansion method
• CarboQC Lab and at-line beverage carbonation
  meter

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Basics of CO2 analysis

• What are the fundamental laws involved?
• How can the fundamental laws be applied to solve
  practical problems?
• How is the CO2 solubility influenced and what are
  the consequences?

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Fundamental gas lawsin beverage CO2 measurement
c concentration ? absorption / solubility p
pressurem mass M molar mass V volume
R gas constant Z compression factor T
temp.
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CO2 measurement units
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Combining the fundamental laws
1 What happens in a bottle/can/chamber?
p1GV1GM/(RT1GZ1) gas mass in gas volume V1G
p1LV1L ? 1 gas mass
dissolved in liquid volume V1L
Initial state (1) before volume / temperature /
solubility change no equilibrium or
equilibrium between phases
p2V2GM/(RT2Z2) gas mass in gas volume
V2G
p2V2L ? 2 gas
mass dissolved in liquid volume V2L
Final state (2) after volume / temperature /
solubility change equilibrium
between phases
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Combining the fundamental laws
2 What happens in a bottle/can/chamber?
Equilibrium pressure in final state (2)
p2 ?
L ? / (M/(RT0Z0))
Gas solubility (Volumes of dissolved gas per
volume of liquid at standard conditions)
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CO2 absorption coefficient

• CO2 absorption
• coefficient /solubility isinfluenced by
• temperature
• sugar
• acids flavors
• CO2 pressure
• dissolved air
• etc.

From Rammert / Pahl, Brauwelt Nr. 12 Nürnberg
1991
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Non-equilibrium state at bottle/can filling
At filling Most CO2dissolved in
beverage,little CO2 in headspaceif not actively
enriched
Equilibrium CO2distributed approx.proportional
to liquidto headspace ratio
HeadspaceCans 3...5Bottles 5...12
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Headspace related temperature effect
CO2 dissolvedin beverage at 40F / 4C
in equilibrium state
CO2 dissolvedin same beverage at 70F/ 21C
inequilibrium state
Beveragecontainere.g. 10headspace
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Multiple Volume Expansion Method

• What happens to the gas partial pressures when
  the volume of the measuring chamber is expanded?
• How and why does the Multiple Volume Expansion
  Method work?
• What are the results?

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CO2 and air equilibrium pressures as a function
of volume expansion
? The air pressure decreases excessively because
the solubility of air is much lower than that
of CO2 !
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CO2 measurement w/o air compensation
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CO2 measurement w/o air compensation
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CO2 error due to dissolved air
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How does the Multiple Volume Expansion Method
work?

• A measuring chamber is completely filled with
  sample and sealed.
• The volume of the measuring chamber is expanded.
• Pressure and temperature equilibrium is
  generated.
• Equilibrium pressure and temperature are
  measured.
• The measuring chamber volume is further expanded,
  equilibrium is generated and pressure and
  temperature are again measured.
• The two pressures/temperatures are used for CO2
  determination and dissolved air compensation.

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CarboQCMultiple Volume Expansion Method
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Why does the Multiple Volume Expansion Method
work?

• The Multiple Volume Expansion method makes use of
  the fact that the solubility of CO2 is much
  higher than that of air.
• By expanding the volume of the measuring chamber
  the partial pressures of CO2 and air change very
  differently.
• Therefore CO2 and air partial pressures can be
  distinguished and the effect of dissolved air
  removed.

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CarboQCMultiple Volume Expansion - Results
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CarboQC Lab and at-line beverage carbonation
meter

• New patented MVE Multiple Volume Expansion method
• No influence from dissolved air
• For accurate and traceable CO2 measurements

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CarboQC
Measuring chamber
Display
Keypad
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CarboQC Rear view
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CarboQC
Water-tight connection plug
ON / OFF switch
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CarboQC withsemi-automaticfilling device
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Specifications of the CarboQC

• Measuring range
• 0 to 12 g/l (0 to 6 Vol.) at 30C (86F)0 to
  20 g/l (0 to 10 Vol.) lt 15C (59F)

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Specifications of the CarboQC

• Repeatability 0.005 bar (0.07 psia)
• 0.05C (0.1F)
• 0.01 g/l (0.005 Vol.)
• Reproducibility 0.015 bar (0.21 psia)
• 0.1C (0.2 F)
• 0.05 g/l (0.025 Vol.)

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Benefits of the CarboQC

• No influence from dissolved air
• Highly accurate absolute pressure sensor ? no
  weather and sea level influence
• Very accurate temperature measurement due to
  impeller technique
• No calibration/adjustment with reference methods
  or CO2 standards necessary
• Zero point calibration simply with (tap) water
• Small amounts of sample
• Fast and accurate results in a wide temperature
  range
• Versatile and easy to use with PFD filling device

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Comparison to Zahm Nagel results

• Zahm Nagel requires snifting (venting) at
  bottles to decrease air influence ? leads to
  temperature headspace volume dependent loss of
  CO2
• Zahm Nagel is subject to full influence of air
  at cans due to no snifting being possible
• Zahm Nagel pressure and temperature measurement
  provides only limited accuracy
• Headspace related temperature effect causes
  deviations

• The CarboQC provides more precise results
  than Zahm Nagel
• CarboQC results are lower due to lack of air
  influence

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Comparison to membrane-type instruments
CarboQC
Membrane-type

• Drift due to change of membrane permeability
• Frequent recalibration necessary
• Influenced by sample pressure and flow rate
• Limited temperature range of calibration
• Large amount of sample required

• Reliable measurement, no drift
• Virtually no calibration necessary
• No influence of sample pressure and flow rate
• Accurate results on cold and warm samples
• Small amount of sample

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CarboQC summary

• Lab and at-line beverage carbonation meter
• Patented Multiple Volume Expansion method? No
  influence from dissolved air
• Easy to use, fast and accurate
• Wide measurement temperature range
• Small amount of sample