Electro-Chemical Devices (ECD) CA6 Hardness Analyzer - Manual (Page 29)

3.0 OPTIONS
Two popular options are the Dilution Module, allowing over range
samples to be diluted into the proper measurement range and the
Oxidation Module, used to break down complex molecules into
measurable constituents.
3.1 Dilution Module
For high range samples a dilution module is added to the hydraulic
configuration. A second 3-way valve is added to the flow train. The Loop
On and Loop Off functions are used to program the steps of the dilution.
Below is a description of the steps of the dilution.
Sample and DI water must be connected to the correct position, verify:
#1 (sample) connected to the left side of the selection valve and #2
(deionized water) to the right side of the selection valve.
1) Drain function
The first step of every measurement cycle is a drain cycle. This function opens the pinch valve to
empty the colorimetric cell.
2) Rinse Function #1 or #2 Loop On/Loop Off
With Loop On, the loop pathway is open and the sample passes through the loop and the hydraulic
lines to drain.
With Loop Off, the loop pathway is closed trapping a small sample in the loop while the sample
passes through the other side of the valve to drain.
This function also allows the loop to be filled with the sample and then to trap and hold the exact
quantity of sample to be diluted.
The “Rinse 1” picture shows rinse function with sample connected to #1 and loop on.
The “Rinse 2” picture shows rinse function with DI water connected to #2 and loop on.
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