Online residual chlorine monitors for most on-line chlorine monitoring applications.



  • Proven colorimetric DPD chemistry
  • Reliable, low maintenance design
  • Range of 0 – 10 ppm
  • EPA accepted method
  • User selectable sample times
  • Removable sample cuvette
  • Two relay outputs, plus 4-20 mA and RS-485 with Modbus
  • Bright backlit display

Online Chlorine Analyzers Product Description

Global Water’s new CL500 continuous online chlorine analyzers are accurate and reliable instruments for free or total chlorine residual measurement. The online residual chlorine monitors use the reliable and economical, colorimetric DPD (N,N-diethyl-p-phenylenediamine) chemistry, proven to be the most accurate method for measuring free or total residual chlorine. With no troublesome mixing or pump components to wear out, the online chlorine analyzers provide reliable operations with minimal maintenance.

The CL500 continuous online chlorine analyzer’s user selectable sample settings conserves reagents by allowing you to set the cycle time from 90 seconds up to 10 minutes. The online residual chlorine monitor’s low volume reagent and sample chamber saves on reagent costs and decreases water consumption. A removable sample cuvette allows for simple cleaning and maintenance, and the online chlorine analyzer’s viewable sample chamber allows a clear view of the sample cuvette while the instrument is sampling.

The CL500 continuous online chlorine analyzers provide a programmable 4-20 mA output signal that may be used with the GL500 datalogger for reporting purposes or to control a chemical feed system.  There are also two user-selectable Hi/Low limit relays on the online residual chlorine monitor that can trigger an AD200 autodialer or a local alarm system in the event of a system problem.  The online chlorine analyzer’s small footprint and corrosion resistant NEMA 4X (IP66) enclosure allows for a simple installation that will fit in almost any space.

The CL500 continuous online chlorine analyzers come with inline pressure regulator, replacement tubing/cuvette kit (one year supply), and owners manual.
NOTE: Reagents for the online residual chlorine monitors must be purchased separately.

Online Chlorine Analyzers Product Specifications

Range:  0 – 10 mg/l
Cycle Time:  User Selectable: 90 seconds to 10 minutes
Resolution:  0.01 mg/l
Accuracy:  ± 5% or 0.03 mg/l of Cl2 whichever is greater
Method:  USEPA accepted DPD method of analysis
Standard Outputs:  4-20 mA and RS-485 with Modbus
User Alarms:  2 User Selectable Alarms (Form C 240VAC 2A)
Operating Temperature:  5° to 40°C (41° to 104°F)
Input Pressure:  1 – 200psi
Display:  Backlit LCD
Enclosure:  ABS Plastic, NEMA 4X, IP66
Power:  100 – 240 Volt Auto Switchable 47-63hz
Certifications:  CE, UL, CSA, (ETL, ETLc)
Shipping Dimensions:  16″ x 16″ x 10″ (41cm x 41cm x 26cm)
Shipping Weight:  8lbs (3.6kg)

Online Chlorine Analyzers Options

CL500 Online Chlorine Analyzers (PN# DN1000)
NOTE: The CL500 is intended for cord connection.  A power cord is not included.


Online Chlorine Analyzer Power Cord (PN# 00-302)

09951GW Dry Reagent Set for Free Chlorine (30 Day) (PN# DN1105)

09952GW Dry Reagent Set for Total Chlorine (30 Day) (PN# DN1115)

09953GW Dry Reagent Set for Free Chlorine (60 Day) (PN# DN1125)

09954GW Dry Reagent Set for Total Chlorine (60 Day) (PN# DN1135)

09939-G Replacement Tubing/Cell Kit (PN# DN1200)

CL500-ZCK-120 Zero Calibration Kit, 120V (PN# DN1210)

CL500-ZCK-240 Zero Calibration Kit, 240V (PN# DN1220)


CL200 Chlorine Meter
Includes sample cup with cap, 5pks of 10 reagent tablets, batteries, and a 48 inch neckstrap.

GL500-7-2 Multichannel DataLogger
Features 7 analog channels and 2 pulse channels, USB and serial communication port, and includes software and cables.  Requires an external 12 VDC power source.

CR500 Circular Chart Recorder

MRC 5000 Circular Chart Recorder with Display

AD200 Voice Alarm Autodialers