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5. OPERATION PROCEDURES
Water Quality Readout
Ion exchanged water and distilled water processed by this unit conform to the JIS K0557 A4 standard.
JIS K0557 standard
JIS K0557 standard is a standard for pure water used for testing industrial water and plant wastewater.
The classification and quality of pure water are defined as shown in the table below.
Item
Classification and quality
A1 A2 A3
A4
Electrical
conductivity
mS/m (at25 °C) 0.5 or less
0.1 or less
0.1 or less
0.1 or less
Specific
resistance
m
Ω
cm (at25 °C) 0.2 or more
1 or more
1 or more
1 or more
Total organic
carbon
mg/L
1 or less
0.5 or less
0.2 or less
0.05 or less
Zinc
μ
g/L
0.5 or less
0.5 or less
0.1 or less
0.1 or less
Silica
μ
g/L
-
50 or less
5.0 or less
2.5 or less
Chloride ion
μ
g/L
10 or less
2 or less
1 or less
1 or less
Sulfate ion
μ
g/L
10 or less
2 or less
1 or less
1 or less
・
A1 is used for cleaning instruments, or as material for pure water of A2~A and A3.
・
A2 is used for general tests and as material for pure water of A3~A and A4.
・
A3 is used for preparation of reagents and microanalysis.
・
A4 is used for microanalysis. (Refined by distillation using a quartz glass distillation unit, or a
procedure which yields equivalent water quality)
The
specific
resistance
is shown as reference. The original standard does not contain specific
resistance.