YOKOGAWA UV700G, User Manual

Page: 44 / 131

<5. Calibration>
5-5
IM 12K01B02-01E
CAUTION
• Make sure to use distilled water to dilute the span calibration solution. Never use the tap
water, groundwater, or industrial water.
• Use 2 ampoules of H calibration solution when preparing the span calibration solution of 1.1
Abs to 2.5 Abs (110 m
-1
to 250 m
-1
). In this case, the concentration value of span calibration
solution is double the concentration value described on the ampoule.
• Use 4 ampoules of H calibration solution or 2 ampoules of H II calibration solution when
preparing the span calibration solution of 2.6 Abs to 5.0 Abs (260 m
-1
to 500 m
-1
). In this
case, the concentration value of span calibration solution is 4 times the concentration value
described on the ampoule for H calibration solution, and double the H II calibration solution
ampoule.
l
How to prepare span calibration solution of acid potassium phthalate standard
solution (standard solution for UV calibration)
Normally calibration with the common span calibration solution is available; also, UV calibration
with acid potassium phthalate is possible.
Preparation:
Acid potassium phthalate: using the special grade chemicals, dried for 1 hour at a
temperature of 120 8C, and cooled in desiccators
Zero solution (distilled water): approximately 3 L
1L Beaker: 1
2L Measuring flask: 1
Electronic balance: 1 (accuracy shall be within 1 mg)
Cleaning bottle: 1
1. Determine the requirement of acid potassium phthalate from the following table according to
the measurement range.
Requirement of
acid potassium
phthalate when
compounded in
2 L
Concentration
of span
calibration
solution
Light absorption
when the
temperature of
calibration
solution is 25 8C
(absorption factor)
Light absorption
when the
temperature of
calibration
solution is 20 8C
(absorption factor)
Light absorption
when the
temperature of
calibration
solution is 30 8C
(absorption factor)
UV measurement
range
100 mg 50 mg/L
0.44 Abs
(44 m-1)
0.43 Abs
(43 m-1)
0.45 Abs
(45 m-1)
0.1 Abs to 0.5 Abs
(10 m-1 to 50 m-1)
200 mg 100 mg/L
0.87 Abs
(87 m-1)
0.85 Abs
(85 m-1)
0.89 Abs
(89 m-1)
0.6 Abs to 1.0 Abs
(60 m-1 to 100 m-1)
400 mg 200 mg/L
1.74 Abs
(174 m-1)
1.70 Abs
(170 m-1)
1.78 Abs
(178 m-1)
1.1 Abs to 2.5 Abs
(110 m-1 to 250 m-1)
800 mg 400 mg/L
3.48 Abs
(348 m-1)
3.40 Abs
(340 m-1)
3.56 Abs
(356 m-1)
2.6 Abs to 5.0 Abs
(260 m-1 to 500 m-1)
CAUTION
The calibration solution of acid potassium phthalate has a temperature characteristic. The
temperature characteristic is (4.5 3 10-3) Abs/ 8C at a temperature of 5 8C to 30 8C. Measure the
temperature of calibration solution to calculate the light absorption during calibration.
Calculation method:
Light absorption of calibration solution = Light absorption of calibration solution at a temperature
of 25 8C 3 (1 + (temperature of calibration solution - 25) 3 0.0045)
(The above table shows light absorptions also at 20 8C and 30 8C as a reference.)