Electro-Chemical Devices (ECD) CA6 Hardness Analyzer - Manual (Page 41)

the sample tube in a gallon of De-ionized water, Press RUN ONLINE. After 1 hour, 5 cycles will be
completed. Press RUN, Emergency Stop, RUN, RESET Emergency Stop. The analyzer will be in Standby
Mode (WAIT). Press Display, Data log, average the last 3 absorbance values. Enter the average in the
Blank window of the Service Menu.
7.2 Slope Calibration (Factor)
Set the value of the standard solution to be used for the calibration by pressing PROGRAM →
CALIBRATION MENU → STANDARD, enter the value of the calibration solution.
This procedure is for a manually performed slope calibration (Factor). (See section 7.3 below for a step
by step guide)
• Disconnect the sampling tubing from the sample line or fast-loop reservoir (if present),
• Place sample tube into a container of standard solution. When a new analysis cycle begins, the
analyzer will sample the standard solution.
• The absorbance detected by the analyzer is assumed as the absorbance produced by the
standard solution.
• The stored BLANK value is subtracted from the Standard Solution Absorbance and the factor
value is calculated. The FACTOR is manually entered by pressing and holding the CAL key (3-10
seconds) in the CALIBRATION MENU until the FACTOR value changes. This operation will replace
the stored FACTOR value. It can only be executed after a completed analysis cycle, with the
analyzer in Stand-By (Wait) condition.
It is recommended that at least three analysis cycles be run with standard solution before proceeding
to a new FACTOR calibration.
The FACTOR Calibration can be overwritten in the Service Menu by entering a user determined value.
This could be an average of the absorbance values determined by several cycles of Standard Solution.
Place the sample tube in a gallon of Standard Solution, Press RUN ONLINE. After 1 hour, 5 cycles will be
completed. Press RUN, Emergency Stop, RUN, RESET Emergency Stop. The analyzer will be in Standby
Mode (WAIT). Press Display, Data log, average the last 3 Absorbance values. The Standard Solution value
divided by the average absorbance equals the FACTOR. Enter the value in the FACTOR window of the
Service 2 Menu. The Service 2 Menu is accessed by pressing ¼” to the left of the Close (X) of the Service
1 Menu.
7.3 Step by Step Manual Calibration
Before performing a manual calibration the operator should disable the 4-20 mA output. To disable the
4-20 mA output press PROGRAM → SETTINGS → OUTPUT SIGNAL → ENABLE/DISABLE.
1. Disconnect the sampling tubing coming from the fast-loop reservoir (if present).
2. With the sampling tube connected to port #1 of the 3 way valve, place the other end in a
container of distilled water (500ml – 1000ml). Keep the door Closed during operation.
3. From the Main Menu select RUN → Cycle Ch 1.
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