KROHNE OPTIMASS Sensors Concentration Measurement EN - Manual (Page 10)

3
CONCENTRATION MEASUREMENT
10
OPTIMASS
www.krohne.com 01/2014 - 4000733002 - AD OPTIMASS Concentration R04
3.2.7 Alcohol
Alcohol concentration can be shown by either mass or volume. The measurement is calculated
using density and temperature to determine the percentage of ethanol to water.
Alcohol by mass Alcohol by mass Alcohol by mass Alcohol by mass
The concentration of alcohol by mass is shown as a percentage from 0...100% in the temperature
range -20°C...+40°C / -4°F...+104°F, according to OIML R22:1973 alcoholometric table I.
Alcohol by volume Alcohol by volume Alcohol by volume Alcohol by volume
The concentration of alcohol by volume is shown as a percentage from 0...100% in the
temperature range -20°C...+40°C / -4°F...+104°F, according to OIML R22:1973 alcoholometric
table III. The reference point for concentration by volume is 20°C
3.2.8 Concentration by mass
A mixture or solution with total mass (M
T
) contains the mass (M) of one component. The
concentration by mass (C
M
) of that component is:
Concentration by mass will not change with temperature.
This formula cannot be used in its current form in a continuous process because it's not possible
to determine the mass of each component. However, if the density of each component is known,
then it is possible to calculate the mass using the formula:
3.2.9 Product A and Product B
The concentration formulae in previous sections requires the density of both Product A and
Product B. Because the density of a product normally changes with temperature, the formulae
for Product A and Product B have a temperature and temperature squared term to model this
behaviour.
Product A is calculated using the formula:
Product A = density of Product
A
at 20°C / 70°F + temperature coefficient
A
x (temperature - 20) +
C
M
concentration by mass
M mass
M
T
mass total
C
M
concentration by mass
ρ
A
density of product A
ρ
B
density of product B
ρ
M
density of the mixture
AD_Concentration_en_140124_4000733002_R04.book Page 10 Tuesday, January 28, 2014 9:28 AM