SOPTOP FCL35 Handheld Free Chlorine Analyzer
| Brand | SOPTOP |
|---|---|
| Origin | Shanghai, China |
| Model | FCL35 |
| Detection Parameter | Free Chlorine (Single-Parameter) |
| Form Factor | Pen-Type Portable Analyzer |
| Measurement Range | 0.05–10.00 ppm |
| Resolution | 0.01 ppm |
| Accuracy | ±1% F.S. |
| Temperature Range | 0.0–60.0 °C |
| Calibration | Two-Point (0 ppm + User-Selectable Standard) |
| Display | 22 × 32 mm Multi-Line LCD with Energy-Saving Backlight |
| Data Storage | 10 Sets |
| IP Rating | IP67 |
| Power Supply | 1 × AA Alkaline Battery (1.5 V) |
| Auto-Power-Off | After 6 min of inactivity with data retention |
Overview
The SOPTOP FCL35 Handheld Free Chlorine Analyzer is a compact, field-deployable electrochemical sensor system engineered for rapid, on-site quantification of free chlorine concentration in aqueous solutions. Unlike broad-spectrum residual oxidant meters, the FCL35 employs amperometric detection with a dedicated chlorine-selective electrode and integrated temperature compensation—ensuring stable output across dynamic environmental conditions. Its pen-type architecture conforms to ISO 7393-2 and ASTM D1253 standards for residual chlorine measurement in drinking water, wastewater effluent, swimming pools, and cooling tower systems. Designed for operational simplicity without sacrificing metrological integrity, the instrument delivers trace-level resolution (0.01 ppm) and full-scale accuracy within ±1%, meeting routine QA/QC requirements in municipal utilities, facility management, and third-party environmental testing laboratories.
Key Features
- Amperometric free chlorine sensing with built-in temperature compensation (0.0–60.0 °C), eliminating manual correction errors
- Two-point calibration protocol supporting zero-point (0 ppm) and user-defined standard (e.g., 2.0 or 5.0 ppm Cl₂), compliant with EPA Method 334.0 calibration guidelines
- IP67-rated enclosure ensuring dust-tight operation and submersion resistance up to 1 m for 30 minutes—suitable for outdoor, wet, or high-humidity environments
- Multi-line LCD display (22 × 32 mm) with energy-efficient backlighting for legibility under low-light conditions, including nighttime inspections or underground utility vaults
- Auto-hold function freezes real-time readings for documentation; auto-power-off (6-minute timeout) preserves battery life while retaining last 10 measurements in non-volatile memory
- Modular interface compatible with the optional SOPTOP A530 flow-through cell for continuous monitoring applications—enabling integration into inline process loops or automated sampling stations
Sample Compatibility & Compliance
The FCL35 is validated for use with potable water, chlorinated pool water, secondary-treated wastewater, and industrial process water where free chlorine concentrations fall between 0.05 and 10.00 ppm. It excludes interference from monochloramine at typical disinfection ratios (<0.5 mg/L NH₃) and demonstrates minimal cross-sensitivity to bromine or ozone when operated per manufacturer’s sample-handling protocols. The analyzer complies with GLP documentation requirements through timestamped data logging and supports audit-ready reporting when paired with SOPTOP’s optional PC connectivity kit (not included). While not FDA 21 CFR Part 11-certified as a standalone unit, its calibration traceability aligns with ISO/IEC 17025-accredited laboratory practices for method validation.
Software & Data Management
Data acquisition is performed via direct visual readout; the device does not feature Bluetooth or USB connectivity in its base configuration. All stored values (up to 10 entries) retain measurement time stamps and associated temperature readings. For regulatory reporting, users may manually transcribe results into LIMS-compatible spreadsheets or SOPTOP’s optional LogView desktop software (v2.1+), which enables CSV export, trend graphing, and calibration history archiving. Each unit ships with a NIST-traceable calibration certificate referencing certified chlorine standard solutions (e.g., Hach 1410928), satisfying internal quality audits and external accreditation reviews under ISO 9001 and ISO/IEC 17025 frameworks.
Applications
- Routine verification of chlorine residuals at water treatment plant discharge points and distribution system entry points
- Swimming pool and spa maintenance compliance checks per CDC Model Aquatic Health Code (MAHC) Section 4.3.2.1
- Pre- and post-disinfection monitoring in food processing rinse water systems (FSMA-aligned environmental monitoring)
- Field validation of point-of-use (POU) and point-of-entry (POE) chlorine removal systems
- Educational laboratory instruction in environmental chemistry and water quality analysis curricula
FAQ
Does the FCL35 measure total chlorine or only free chlorine?
The FCL35 is specifically configured for free chlorine (HOCl/OCl⁻) detection using an amperometric membrane electrode. It does not quantify combined chlorine (chloramines) or total chlorine without additional reagent-based conversion steps.
Is the A530 flow-through cell required for all measurements?
No—the A530 is optional and intended only for continuous, unattended sampling. For spot-checking, dip-mode operation is fully supported and factory-validated.
Can the FCL35 be calibrated with non-SOPTOP standards?
Yes, provided the reference solution is certified for free chlorine content and traceable to NIST SRM 3112a or equivalent, and falls within the 0–10 ppm range.
What battery type is used, and how long does it last?
One standard AA alkaline battery (1.5 V) powers the unit for approximately 200 hours of intermittent use; low-battery indication appears prior to critical voltage drop.
How often should calibration be performed in routine field use?
Daily calibration is recommended for critical applications (e.g., regulatory reporting); for general surveillance, calibration before each shift or after every 10 measurements ensures optimal reproducibility.
