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20
GF 9950-10 Six Channel Transmitter
• % Recovery is a derived function based on
fl
ow rate, in a
reverse osmosis system.
• To measure % Recovery, the 9950 must have two
fl
ow
sensors connected. They may be located in the Feed line,
the Concentrate line or the Permeate line.
• The 9950 provides 3 different methods for calculating
Recovery to accommodate any con
fi
guration.
• Both
fl
ow sensors must use the same time base and units
of measure.
% Recovery
R embrane
R embrane
R embrane
Feed
Concentrate
Permeate
% Recovery A: (
Permeate
÷ Feed)
x 100
In the Setup menu, select the option that states
% Recovery A,
FEED: PERMEATE
% Recovery B:
Permeate
÷ (
Permeate
+ Concentrate) x 100
In the Setup menu, select the option that states
% Recovery B,
PERMEATE: CONC
% Recovery C: [(
Feed
- Concentrate) ÷
Feed
] x 100
In the Setup menu, select the option that states
% Recovery C,
FEED: CONC
R embrane
R embrane
R embrane
Feed
Concentrate
Permeate
Feed
Concentrate
R embrane
R embrane
R embrane
Permeate
Derived Functions
When two of the same type of measurement (either primary or secondary) are present, the 9950 can calculate several derived functions
from like pairs of measurements. Set-up menu located in the Options menu, refer to page 59.
Up to four derived Functions can be de
fi
ned and used as the source for a loop output or relay control.
Derived calculations can be viewed in the View Mode.
• Flow, Temperature, Pressure, Conductivity and Level measurements must have matching units.
(Flow channels must also have same time base).
• Conductivity channels will automatically scale to
μ
S/cm before the function calculation is made.
•
Three types of derived measurements can be applied to any set of sensors, regardless of type.
• Ratio:
Measurement 1 ÷ Measurement 2 or Measurement 2 ÷ Measurement 1
• Delta (Difference): Measurement 1 - Measurement 2 or Measurement 2 - Measurement 1
• Sum:
Measurement 1 + Measurement 2
• Custom labels can be assigned to Derived Functions for ease of identi
fi
cation.
• % Passage and % Reject are derived functions based on
conductivity measurements only, speci
fi
cally for use in reverse
osmosis systems.
• % Passage is the amount of contaminates remaining in the
product water compared to the level of contaminates in the feed
water. For example, if the feed water measures 375
μ
S and the
product water measures 18.75
μ
S, the % Passage is
(18.75/375) x 100= 5%
• % Reject is the amount of contaminates rejected to the
concentrate water compared to the amount of contaminates
in the feed water. For example, if the feed water measures
375 uS and the product water measures 18.75 uS the % reject is
[1-(18.75/375)] x 100 = 95%
• Decreasing Reject values and increasing Passage values
usually indicate a problem with the RO membrane.
% Passage and % Reject
% Passage:
(Permeate ÷ Feed) x 100
% Reject:
[1 - (Permeate ÷ Feed)] x 100
RO Membrane
RO Membrane
RO Membrane
Feed
Concentrate
Permeate