The MP-5F Chlorine Sensor
Formerly known as H2 and MP-Free, the MP-5F is our second-generation reagentless chlorine sensor. A redesigned wet-end delivers years-long wear life, single-cycle priming, and a chlorine sensor you can service in the field.
NSF-61
The MP-5F takes every lesson from thousands of field hours and turns it into a sensor that is easier to service, lasts longer between maintenance, and delivers tighter accuracy — without giving up the reagentless, membrane-free simplicity operators rely on.
What Your Operation Will Feel
Longer life, faster priming, and serviceable in the field — the redesign operators asked for.
Years-Long Wear Life
PEEK bearing-grade wear parts are designed for long service life. Planned maintenance is scheduled once a year, using the service parts appropriate for the installed configuration.
Primes in a Single Cycle
The redesigned wet-end primes in one cycle where the prior generation averaged four. That means faster startups, quicker recovery after air exposure, and shorter service calls.
Field-Serviceable Chlorine Sensor
Potted, polished chlorine sensors are engineered for field replacement and ship factory pre-calibrated. Swap in the field and go — less downtime and a lower cost of ownership.
Consistent Electrode Conditions
The sensor generates flow across its electrodes while the cleaning system polishes their surfaces, reducing measurement variables and routine cleaning work.
Redesigned pH & Cover
A no-thread pH sensor and a gasket-free tongue-and-groove cover make routine service faster and more reliable, with fewer parts to seat and seal.
Built to Keep Reading
A longer impeller resists metal filings and the self-cleaning system keeps the sensor surface clear — accurate readings whether wet-tapped, side-stream, or immersed.
Still Reagentless. Still No Membranes.
The MP-5F keeps the proven three-electrode amperometric core — no reagents to replenish, no membranes to replace, and a self-cleaning system that keeps the sensor surface clear without operator intervention. Five parameters, one probe, a reading every 60 seconds.
Know the parts before you open the sensor.
See the service components and cleaning media up close. Match the sensor generation and service kit to the current manual before starting work.
Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Reagentless 3-electrode amperometric (no membrane) |
| Free Chlorine Range | 0–10 mg/L (ppm) |
| Limit of Detection | 0.03 mg/L (30 ppb) |
| Resolution | 0.001 mg/L |
| Accuracy | ±5% of reading or 0.04 mg/L (0.04 ppm), whichever is greater |
| Response Time (T90) | 90 seconds |
| Chlorine Measurement pH Range | 6.5–9.0 pH |
| Standalone pH Measurement Range | 2–12 pH |
| Conductivity Range | 50–15,000 µS/cm |
| Sample Temperature | 0–45°C |
| Operating Temperature | 1–45°C |
| Ambient Temperature | −10–55°C |
| Pressure Range | −0.7–10 bar (vacuum to 145 psi) |
| Operating Flow | 0–4 m/s |
| Storage Temperature | −20–40°C |
| Input Power | 12–24 VDC, 100 mA |
| Communications | Modbus RTU |
| Master Specification | Halogen Master Specifications v19 |
| Ingress Protection | IP65 |
| Weight | 1 kg (2.2 lb) |
Frequently Asked Questions
What was the MP-5F formerly known as?
The MP-5F was introduced as H2 and also appeared on this website as MP-Free. MP5F is the same current name written without a hyphen. Earlier MP5 / MP5A manuals and studies remain available separately; confirm the generation and configuration before using older specifications or ordering parts.
What is the MP-5F chlorine sensor?
The MP-5F is Halogen’s second-generation reagentless multiparameter chlorine sensor. It builds on a decade of MP5 deployments with a redesigned wet-end that delivers years-long wear life, single-cycle priming, a field-serviceable chlorine sensor, and consistent electrode cleaning.
What parameters does the MP-5F measure?
The MP-5F measures free chlorine, pH, ORP, conductivity, and temperature from a single probe — no reagents and no membranes.
How long do the wear parts last?
Planned maintenance is once a year. Wear-part service should be performed with the applicable service parts for the installed configuration; follow the current maintenance documentation for replacement and inspection instructions.
Can the chlorine sensor be replaced in the field?
Yes. The potted, polished chlorine sensor is designed for field replacement and ships factory pre-calibrated. Operators swap it on-site with no bench calibration and minimal downtime.
Is the MP-5F compatible with existing Halogen systems?
Yes. The MP-5F keeps the same operational philosophy and D20 controller compatibility as the MP5, making it a natural upgrade path for existing deployments.
Is the MP-5F NSF-61 certified?
Yes. The MP-5F is NSF/ANSI 61 certified for use in contact with drinking water.
D20 + MP5F Free Chlorine product guide
Formerly MP5A · Updated R1.18 draft for review, with earlier manuals available for existing equipment.
View the MP5F guide (formerly MP5A) — R1.18 DRAFTDownload the MP5F data sheet
Get the MP5F specifications, wiring information, dimensions, and installation details delivered through the HubSpot download form.
A clearer way to monitor drinking water.
Get the Halogen MP5F drinking-water brochure for an overview of free-chlorine monitoring, direct-pipe installation, self-cleaning sensing, and the MP5F platform.
- Free-chlorine monitoring for drinking-water systems
- Wet-tap, immersion, side-stream, and tee installation options
- Reagent-free, membrane-free operation with no sample-to-drain waste stream
Get the free brochure
Complete the form for immediate access to the PDF.
Ready to put the MP-5F to work?
Request a quote, schedule a demo, or talk to our engineering team about the MP-5F for your application.
Big tank. Simple solution.
Measure directly in your tank or reservoir—with no external sample pump, drain, or return line.
MP5 Free
A closer look at the suspension bracket and cable entry on the free chlorine model.
View mounting detail ↗One mount. No external sample loop.
The integrated impeller creates local flow across the sensing surface. You can monitor directly in a tank or reservoir without an external sample pump, drain or return line.
Use the sealed IP68 immersion assembly. Confirm depth, cable length and an approved support arrangement for your installation.
See the reservoir installation →Product renders show mounting details; final configuration follows the installation guide. Open any image for a larger view.
MP-5F — formerly known as H2 and MP-Free.
Looking for MP5 or MP5A? Those names remain in earlier manuals and field studies. Use the MP5 / MP5A documentation page for those installations, and the product-name reference to match the current name to your documents.
Specify the mounting arrangement, pH option, operating conditions and cable length when requesting a quote. Confirm the generation and complete part number before ordering replacement parts. Hot-water variants require confirmation of the qualified model and operating limits.