Hach DR2400 - Page 179

Chlorine, Free
Chlorine, Free
ChlorineFre_PT_Other_DPD_Eng_Ody.fm Page 5 of 6
Method Performance
Precision
Standard: 1.07 mg/L Cl
2
See Section 3.4.3 Precision on page 44 for more information, or if the standard
concentration did not fall within the specified range.
Sensitivity
See Section 3.4.5 Sensitivity on page 44 for more information.
Summary of Method
Chlorine in the sample as hypochlorous acid or hypochlorite ion (free chlorine or
free available chlorine) immediately reacts with DPD (N,N-diethyl-p-
phenylenediamine) indicator to form a red color which is proportional to the
chlorine concentration. Test results are measured at 530 nm.
Required Reagents
Quantity Required
Description Per Test Unit Cat. No.
Reagent Set .......................................................................................................................................................25569-00
Includes:
DPD Indicator Powder................................................................................................ 24 g....................22972-55
Free Chlorine Indicator Solution .....................................................1 mL ................ 473 mL..............23140-11
Free Chlorine Buffer Solution...........................................................1 mL ................ 473 mL..............23141-11
Required Apparatus
Adapter, multi-pathlength cell ...............................................................1 ....................... each....................59466-00
Cylinder, mixing, glass, 100-mL .............................................................1 ....................... each.....................1896-42
Dispenser, fixed volume, 1.0 mL Repipet Jr..........................................2....................... each...................21113-01
Pour-Thru Cell Kit....................................................................................1 ....................... each...................59404-00
Required Standards
Chlorine Standard Solution, Voluette
®
Ampule, 50-75 mg/L, 10-mL........................ 16/pkg..............14268-10
or
Chlorine Standard Solution, Voluette
®
Ampule, 50-75 mg/L, 2-mL.......................... 20/pkg..............14268-20
Water, deionized ................................................................................................................. 4 L .........................272-56
Program 95% Confidence Limits of Distribution
82 1.05–1.09 mg/L Cl
2
Portion of Curve ∆Abs ∆Concentration
Entire range 0.010 0.02 mg/L Cl
2