Chlorine Meters

Free Chlorine and Total Chlorine

Free chlorine measures the chlorine available in forms such as hypochlorous acid and hypochlorite ion. Total chlorine includes free chlorine and combined chlorine, including chloramines. Choose the parameter required by your testing procedure and confirm that the meter or test kit supports it.

Choosing a Chlorine Meter

Compare measurement range, resolution, accuracy and testing method against the expected sample concentration. Portable meters suit spot checks and field testing, while online analyzers support ongoing monitoring at an installed sampling point. Confirm the supported chlorine parameter rather than assuming every instrument measures both free and total chlorine.

Colorimetric Testing and Reagents

Colorimetric chlorine tests use a reagent to develop a color that the instrument measures. Use the specified reagent and follow the procedure for sample volume, mixing and reaction time. Free and total chlorine reagents are not interchangeable, and results depend on correct reagent storage and use within the stated shelf life.

Sample Handling and Measurement Technique

Test samples promptly because chlorine residual can change during storage and handling. For photometric measurements, keep sample cells clean and free of fingerprints, bubbles and residue. Follow the meter’s blanking procedure and observe any limits for sample color, turbidity or interfering substances.

Online Residual Chlorine Monitoring

Online chlorine measurement requires a compatible sensor, analyzer and installation arrangement. Check the specified sample flow, pressure, temperature and pH conditions, along with maintenance and calibration requirements. Confirm available outputs and control functions for the selected analyzer before planning an installation.

Calibration Standards and Verification

Use chlorine standards only as directed by the instrument manufacturer. Some standards are intended for verification rather than user calibration. Match the standard to the supported parameter, concentration and instrument procedure; a reference standard does not replace the reagent required for a sample test.

Applications and Method Requirements

Chlorine testing supports residual monitoring in water treatment, pool and spa maintenance and compatible process water applications. Select equipment and methods appropriate to the sample and intended use. Where a specific test method is required, verify the exact instrument and reagent combination against that requirement.