Section 13420

INSTRUMENTS

2.                    PRODUCTS

2.1    Residual Chlorine Analyzer

A.      Analyzer shall continuously measure free or total (combined) chlorine in drinking water applications.  Unit shall also have the capability of measuring ph or fluoride in addition to chlorine.

B.       Analyzer shall use amperometric technology requiring no reagents.  Units requiring the use of reagents are not acceptable under this specification.  The measuring cell shall be of the three-electrode type, eliminating the need for zero adjustment.

C.       Measurement Ranges:

1.        Chlorine – 0-20 mg/l free or total

2.        pH – 4 to 10

3.        Fluoride – 0.2 – 2.0 mg/l

D.      Accuracy requirement: 0.01 mg/l or 2% F.S.  whichever is greater

E.       Analyzer shall have the capability of continuous measurement

F.       Response Time: Total chlorine: 90% change in less than 5 minutes

                                  Free chlorine: 90% change in lees than 20 seconds

G.       Inlet Pressure Range: 0-60 psi

H.      Water Temperature Range: 41 F to 104 F

I.         Electronics shall be separate from the wetside sample assembly and shall be housed in a NEMA 4 enclosure with 2-line backlit LCD display.  Set-up, calibration, and access to diagnostics shall be via a keypad on the unit.  Input power shall be 110 VAC.  Outputs shall be as follows:

(1)- isolated 4-20 mA for free or total chlorine

(1)- isolated 4-20 fro pH or fluoride

(2)- SPDT relays user configurable for chlorine

(2)- SPDT relays user configurable for pH or fluoride

J.        Unit shall be provided with a flow switch mounted to the inlet wetside to provide

alarm on loss of sample.

K.      Isolation valve shall be provided on the inlet to the wetside assembly to allow

shut-ff of the sample for maintenance

L.       Unit shall be Depolox 3 manufactured by Wallace & Tiernan or equal.