HF Scientific CPP-1 Chlorine Colorimeter

Overview

The HF Scientific CPP-1 Chlorine Colorimeter is a portable, field-deployable photometric analyzer engineered for rapid, on-site quantification of free and total chlorine in drinking water, wastewater, swimming pools, and industrial process streams. Based on the standard DPD (N,N-diethyl-p-phenylenediamine) colorimetric method, the instrument measures absorbance at 515 nm—optimized for the stable pink-to-magenta chromophore formed when chlorine oxidizes DPD reagent. Its optical path employs a precision LED light source and solid-state photodetector, eliminating the need for warm-up time or lamp replacement. Designed for routine compliance monitoring rather than research-grade spectroscopy, the CPP-1 delivers traceable, repeatable results aligned with U.S. Environmental Protection Agency (EPA) Method 334.0 for free chlorine and Method 334.1 for total chlorine. The device operates without external power—powered solely by two AAA batteries—and achieves full operational readiness within 3 seconds of activation.

Key Features

• High-contrast backlit LCD display with intuitive single-button navigation and real-time unit switching (ppm or mg/L)
• Auto-power-off function (after 10 minutes of inactivity) to extend battery life beyond 2,000 measurements per set
• Rugged, IP67-rated enclosure resistant to dust ingress and submersion in 1 m of water for up to 30 minutes—validated for outdoor and wet-lab use
• Fixed-wavelength optics centered at 515 nm with narrow spectral bandwidth (<10 nm FWHM), minimizing interferences from turbidity or background color
• Pre-calibrated factory curves for both free chlorine (PPD/CPPD reagents) and total chlorine (PPD/CPPD + potassium iodide activation), accessible via mode toggle
• Integrated cuvette holder with alignment guide ensures consistent optical path length (10 mm) and minimizes operator-induced variability

Sample Compatibility & Compliance

The CPP-1 accepts 3 mL liquid samples in standard 10-mm-pathlength polystyrene cuvettes (included). It is compatible with HF Scientific’s EPA-compliant reagent kits—including PPD-based formulations (Cat. No. 10500, 10502) and high-capacity CPPD variants (Cat. No. 10500C, 10502C)—each validated for stability, linearity, and interference rejection per Standard Methods for the Examination of Water and Wastewater (20th ed., Sections 4500-Cl G & H). The instrument meets CE marking requirements under the EU Electromagnetic Compatibility Directive 2014/30/EU and Low Voltage Directive 2014/35/EU. While not individually certified to ISO/IEC 17025, its measurement performance conforms to the accuracy and repeatability thresholds specified in ASTM D1253 and ISO 7393-2 for field-portable chlorine analyzers used in regulatory monitoring programs.

Software & Data Management

The CPP-1 is a standalone, non-data-logging instrument; it does not interface with PCs or support firmware updates. All calibration and measurement logic reside in embedded firmware. However, its output format supports direct transcription into LIMS or paper-based QA/QC records. Users may manually record results alongside batch identifiers, date/time stamps, and reagent lot numbers—practices consistent with GLP documentation requirements. For laboratories requiring electronic audit trails, HF Scientific recommends pairing the CPP-1 with its optional data logger accessory (CPP-DL, sold separately), which provides timestamped CSV export compliant with FDA 21 CFR Part 11 when used with validated software.

Applications

• Drinking water distribution system verification (residual chlorine mapping at entry points and dead-ends)
• Swimming pool and spa facility daily safety checks per CDC Model Aquatic Health Code (MAHC)
• Wastewater disinfection contact chamber monitoring prior to discharge
• Validation of chlorine dosing systems during commissioning or maintenance events
• Educational laboratory instruction in environmental chemistry and water treatment principles
• Field screening during emergency response (e.g., post-flooding potable water assessment)

FAQ

Does the CPP-1 require annual calibration verification?
Yes—per EPA guidance, users must verify calibration using NIST-traceable standard solutions (e.g., HF Scientific Cat. No. 10451A, 2.0 ppm Cl₂) before each day’s use or after every 25 samples, whichever occurs first.
Can the CPP-1 measure combined chlorine (chloramines)?
No—the CPP-1 reports total chlorine only when used with total chlorine reagent (Cat. No. 10502); it does not differentiate monochloramine, dichloramine, or nitrogen trichloride species. For speciation, laboratory-based amperometric titration or ion chromatography is required.
Is the instrument suitable for seawater or brackish water analysis?
Not recommended—high chloride matrix (>1,000 ppm Cl⁻) may cause positive bias due to oxidation of residual DPD by dissolved oxygen or transition metals. Pre-dilution and matrix spike recovery testing are advised if applied outside freshwater scope.
What cuvette type is supported?
Only 10-mm-pathlength, UV-transparent polystyrene cuvettes (Cat. No. 10431) are validated for use; glass or quartz cuvettes introduce refractive index mismatch and invalidates factory calibration.
How is traceability maintained across reagent lots?
Each reagent kit includes a Certificate of Analysis referencing NIST SRM 3100 (Chlorine Standard) and reporting lot-specific blank correction values and working range linearity (R² ≥ 0.999).