4 Calibration
15
4
Calibration
Calibration is the adjustment so that the value indicated by the unit corresponds to the actual
value. It is necessary to obtain measurements of high accuracy and maintain the performance
of the unit.
4.1
Calibration Pattern and its Cycle
It is necessary to perform the calibration periodically.
Perform calibration by following the cycle shown below.
◎
: Recommended cycle,
○
: Calibration as necessary
Perform the calibration in the order of "Common zero calibration," "Common span calibration,"
("Individual (UV) span calibration" as necessary), and "TURB Span calibration."
Descriptions for each Calibration
About the Calibration coefficient
Measuring
item
Calibration pattern
Targeted calibration cycle
Procedure
Reference
Before
operation
Every
week
Every
month
When
problems
occur
UV/VIS
Common zero calibration
◎
◎
◎
◎
page 21
Common span calibration
◎
-
◎
◎
page 24
Individual (UV) span calibration
○
-
○
○
page 27
TURB
(turbidity)
Span calibration
◎
-
◎
◎
page 32
Calibration
Description
Common zero calibration
Common zero calibration of UV/VIS using the zero calibration solution (distilled water).
Put the zero calibration solution in the calibration tank. After the measurement value has
stabilized, perform calibration by operating the zero button.
Common span calibration
Common span calibration of UV/VIS using the exclusive common span calibration
solution. Put the span calibration solution in the calibration tank. After setting the
calibration value of UV/VIS and the measurement has stabilized, perform calibration by
operating the span button.
If performing either one of calibrations, set the span calibration value to "0" for the
component that is not being calibrated. By doing this, the span calibration for one
component becomes possible.
Individual (UV) span
calibration
Individual span calibration of UV using the acid potassium phthalate standard solution
(standard solution for UV calibration).
Put the individual span calibration solution in the calibration tank. After setting the
calibration value of UV and the measurement has stabilized, perform calibration by
operating the span button.
Make sure to set the span calibration value of VIS to "0" before performing the calibration.
Span calibration
Span calibration of turbidity using the span calibration solution.
Zero calibration is not required as the common zero calibration for UV/VIS is performed.
Put the span calibration solution for turbidity in the calibration tank. After setting the
calibration value of TURB (turbidity) and the measurement has stabilized, perform
calibration by operating the span button.
Calibration coefficient
Description
Zero calibration coefficient
Indicates misalignment of zero point
Span calibration coefficient
Indicates the gradient of sensitivity
