HF Scientific CLX-Ex2 Online Chlorine & TRO Monitor 28034

HF Scientific CLX-Ex2 Online Chlorine & TRO Monitor (MPN: 28034) with Purge Controller

The HF Scientific CLX-Ex2 Online Chlorine & Total Residual Oxidant (TRO) Monitor (MPN: 28034) is a pressurized, explosion-proof colorimetric analyzer engineered for continuous process water measurement inside hazardous marine and industrial zones. Designed around Standard Methods 4500-Cl G (USEPA-accepted DPD colorimetric chemistry), this unit automates sample intake, reagent injection, optical measurement, and cuvette purging for shipboard Ballast Water Management Systems (BWMS).

Housed in an IP66-rated 316 stainless steel enclosure with an integrated optical viewing window, the CLX-Ex2 pairs a microprocessor-controlled photometer with an IECEx-approved Air Sentinel™ Purge and Pressurization Controller. Before energizing internal electronics, the purge controller verifies positive enclosure overpressure and airflow to safely clear combustible hydrocarbon vapors, qualifying the assembly for Class I, Zone 1 and Zone 2 (Gas Group IIC, T4) hazardous locations. With user-selectable cycle intervals (60 seconds to 10 minutes) and extended-life reagents, the monitor supports up to 90 days of unattended operation depending on ballast pumping schedules.

Model Details

• Model Series: CLX-Ex2 Series (W620 Product Family)
• Manufacturer Part Number (MPN) / Ordering Code: 28034
• UPC: 098268301564
• Purge & Pressurization System: Integrated Air Sentinel™ Purge Controller (supersedes legacy Cyclops Purge Controller)
• Standard Measurement Range: 0.00 – 10.00 mg/L (ppm) Total Residual Oxidant / Total Chlorine (Factory High-Range Option 0.00 – 15.00 mg/L available under P/N 28895)
• Enclosure Construction: 316 Stainless Steel with front viewing window, IP66 ingress protection
• Scope of Delivery: CLX-Ex2 analyzer chassis, Air Sentinel™ purge controller, integral sample pressure regulator, mounting hardware, and IOM manual (Note: DPD Buffer and Indicator reagents are shipped separately).

Technical Details

Compatibility:

• Compatible Reagents:
  • HF Scientific P/N 09991: Total Chlorine / TRO Liquid Reagent Kit (12-month supply based on standard BWMS operational cycles; includes DPD Indicator and Buffer solutions).
  • HF Scientific P/N 09994: Total Chlorine J.A.W. Extended-Life Reagent Kit (12-month supply).
• Compatible Maintenance & Spare Kits:
  • HF Scientific P/N 09950Ex: Replacement Tubing and Borosilicate Measurement Cuvette Kit.
  • HF Scientific P/N 29207: Air Sentinel™ Purge Controller Replacement / Upgrade Kit (retrofits legacy Cyclops-equipped CLX-Ex and CLX-Ex2 units).
  • HF Scientific P/N 28895: Factory-Installed High-Range Calibration & Optics Option (0–15 mg/L).
  • HF Scientific P/N 28896: Extended Cycle Time Configuration (60 sec to 10 min).
• Compatible BWMS Architectures: Electrochlorination (side-stream and full-flow electrolysis), sodium hypochlorite injection, and chlorine dioxide dosing systems requiring IMO D-2 and USCG 46 CFR 162.060 discharge compliance monitoring.

Part Number Cross-References

• HF Scientific / Watts Ordering Code: 28034 (CLX-Ex2 240 VAC Online TRO & Chlorine Monitor)
• UPC / GTIN: 098268301564
• Series / Family Identifiers: CLX-Ex2, W620, SS-CLX-EX2 (Spec Sheet), ES-HF-CLX-Ex2 (Engineering Spec)
• Manual Document Reference: IOM-HF-CLX-Ex2-28920
• Related / Legacy Cross-References:
  • A28031 / 28031: HF Scientific CLX-Ex (Solid 316SS door without viewing window)
  • 28048: HF Scientific CLX-XT2 (Safe-area / non-Ex extended reagent life model with thermoelectric cooler)
  • 29207: Air Sentinel™ Replacement Kit (Replaces legacy Cyclops Purge Controller)

Features

1. IECEx Zone 1 & Zone 2 Pressurized Protection: Integrates the Air Sentinel™ purge and pressurization controller (Ex pxb IIC T4 Gb), maintaining positive enclosure overpressure to prevent ignition of flammable hydrocarbon vapors in tanker pump rooms and hazardous deck spaces.
2. Low-Consumption DPD Colorimetric Chemistry: Uses a precision three-solenoid metering pump (FLOW, PURGE, and REAGENT) to deliver repeatable USEPA-accepted DPD analysis with up to 90 days of unattended reagent autonomy.
3. Dual-Redundant BWMS Process Integration: Combines an isolated 4–20 mA analog loop, bi-directional RS-485 Modbus RTU telemetry, fail-safe alarm relay (ALM COM/NO), and Remote Standby I/O (RSI/RSO) for closed-loop neutralization dosing control.
4. Front Viewing Window & One-Touch Service Mode: Features an armored viewing window on the IP66 316SS door to inspect optical cuvette condition and reagent levels without breaking enclosure pressurization, paired with a dedicated SERVICE button that drains the cuvette and isolates sample flow during maintenance.

Frequently Asked Questions

What is the difference between the HF Scientific CLX-Ex2 (28034) and the CLX-Ex (28031)?

Both models share the same IECEx Ex pxb IIC T4 Gb hazardous-area rating, DPD colorimetric optics, and Air Sentinel™ purge controller. The CLX-Ex2 (MPN: 28034) features an armored optical viewing window built into the 316 stainless steel door, allowing crew members to visually verify LCD readings, alarm status LEDs, cuvette clarity, and reagent bottle levels without depressurizing or opening the enclosure. The CLX-Ex (28031) uses a solid stainless steel door without a window.

How does the Air Sentinel™ Purge Controller protect the CLX-Ex2 in Zone 1 and Zone 2 areas?

The Air Sentinel™ controller continuously regulates instrument air entering the base of the IP66 enclosure to maintain positive internal overpressure. Upon startup, it monitors both air pressure and exhaust flow rate through a timed purge cycle (indicated by a red TIMER LED) to flush out any flammable gas or fuel vapors before closing the internal power relay to energize the analyzer electronics. If enclosure pressure drops below the safe threshold, it immediately cuts mains power to the monitor.

Can the CLX-Ex2 28034 integrate with a ship’s Ballast Water Management System (BWMS) PLC?

Yes. The CLX-Ex2 provides simultaneous isolated 4–20 mA analog output (capable of driving up to 600 ohms) and bi-directional RS-485 Modbus RTU serial communications for real-time TRO data logging and dosing pump control. It also includes a fail-safe Normally Open alarm relay (ALM COM / ALM NO rated at 240 VAC, 2 A) and dedicated Remote Standby Input/Output (RSI / RSO) terminals so the BWMS PLC can automatically place the monitor into standby when ballast pumps are idle.

Are DPD reagents included with MPN 28034, and how long do they last?

No, reagents are shipped separately from the monitor due to chemical shipping regulations. The CLX-Ex2 uses the HF Scientific Total Chlorine / TRO Reagent Kit (P/N 09991), which consists of separate Buffer and DPD Indicator solutions. Depending on the user-selected cycle time (60 seconds to 10 minutes) and monthly ballasting hours, one reagent set provides up to 90 days of continuous unattended operation or up to 12 months under typical intermittent ballast schedules.

What sample water pressure and temperature limits apply to the CLX-Ex2?

The CLX-Ex2 accepts sample water pressures from 0.34 bar to 10.3 bar (5.0 to 150 PSI) via its built-in pressure regulator, discharging to waste at 200 to 400 mL/min. Both the process sample water and ambient surrounding air must remain between 0°C and 55°C (32°F to 131°F) with up to 95% non-condensing relative humidity.