HM Digital (PM-2) External In-Line TDS Purity Monitor 1-4" Quick Connect
HM Digital PM-2 External In-Line TDS Purity Monitor
Continuous monitoring with programmable alerts for any water purification system using 1/4" quick connect fittings
The HM Digital PM-2 monitors total dissolved solids in real-time and alerts you when your RO membrane or DI resin needs replacement. With a 0-200 ppm measurement range and ±2% accuracy, you set the threshold and the PM-2 handles the rest with both visual and optional audible warnings. Factory calibrated and ready to install inline with 1/4" quick connect fittings.
Built for Continuous TDS Monitoring
Programmable Set Points
User-defined TDS thresholds from 2 to 200 ppm in even-number increments, allowing precise control over when alerts trigger
Dual Alert System
Visual warning light (red or yellow, flashing or steady) plus optional 20-second audible alarm when TDS exceeds your set point
Factory Calibrated
Ships pre-calibrated with ±2% accuracy across the full 0-200 ppm range, no setup or adjustment required
1/4" Quick Connect
Standard John Guest-style fittings for easy inline installation, also available in 3/8" or 1/2" configurations
AC Powered
110V/220V compatible with 24.75" cable, no batteries to replace for reliable continuous monitoring
High Pressure Rated
Handles up to 200 psig water pressure in a compact 5" x 2.9" x 2.4" housing weighing just 12 oz
Universal Water Purification Monitoring
The HM Digital PM-2 works with any reverse osmosis system, deionization filter, or water purification equipment that uses 1/4" tubing. Ideal for monitoring RO permeate quality, DI resin exhaustion, or any application where dissolved solids levels indicate filter performance. Compatible with residential under-sink RO systems, aquarium RODI units, laboratory water purification, and commercial water treatment applications. The external inline design allows installation without cutting into housings or modifying existing equipment.
HM Digital has been manufacturing precision water quality instruments since 1998, trusted by aquarium hobbyists, laboratories, and water treatment professionals worldwide.
HM Digital PM-2 External In-Line TDS Purity Monitor
Continuous monitoring with programmable alerts for any water purification system using 1/4" quick connect fittings
The HM Digital PM-2 monitors total dissolved solids in real-time and alerts you when your RO membrane or DI resin needs replacement. With a 0-200 ppm measurement range and ±2% accuracy, you set the threshold and the PM-2 handles the rest with both visual and optional audible warnings. Factory calibrated and ready to install inline with 1/4" quick connect fittings.
Built for Continuous TDS Monitoring
Programmable Set Points
User-defined TDS thresholds from 2 to 200 ppm in even-number increments, allowing precise control over when alerts trigger
Dual Alert System
Visual warning light (red or yellow, flashing or steady) plus optional 20-second audible alarm when TDS exceeds your set point
Factory Calibrated
Ships pre-calibrated with ±2% accuracy across the full 0-200 ppm range, no setup or adjustment required
1/4" Quick Connect
Standard John Guest-style fittings for easy inline installation, also available in 3/8" or 1/2" configurations
AC Powered
110V/220V compatible with 24.75" cable, no batteries to replace for reliable continuous monitoring
High Pressure Rated
Handles up to 200 psig water pressure in a compact 5" x 2.9" x 2.4" housing weighing just 12 oz
Universal Water Purification Monitoring
The HM Digital PM-2 works with any reverse osmosis system, deionization filter, or water purification equipment that uses 1/4" tubing. Ideal for monitoring RO permeate quality, DI resin exhaustion, or any application where dissolved solids levels indicate filter performance. Compatible with residential under-sink RO systems, aquarium RODI units, laboratory water purification, and commercial water treatment applications. The external inline design allows installation without cutting into housings or modifying existing equipment.
HM Digital has been manufacturing precision water quality instruments since 1998, trusted by aquarium hobbyists, laboratories, and water treatment professionals worldwide.
Original: $131.89
-65%$131.89
$46.16Description
HM Digital PM-2 External In-Line TDS Purity Monitor
Continuous monitoring with programmable alerts for any water purification system using 1/4" quick connect fittings
The HM Digital PM-2 monitors total dissolved solids in real-time and alerts you when your RO membrane or DI resin needs replacement. With a 0-200 ppm measurement range and ±2% accuracy, you set the threshold and the PM-2 handles the rest with both visual and optional audible warnings. Factory calibrated and ready to install inline with 1/4" quick connect fittings.
Built for Continuous TDS Monitoring
Programmable Set Points
User-defined TDS thresholds from 2 to 200 ppm in even-number increments, allowing precise control over when alerts trigger
Dual Alert System
Visual warning light (red or yellow, flashing or steady) plus optional 20-second audible alarm when TDS exceeds your set point
Factory Calibrated
Ships pre-calibrated with ±2% accuracy across the full 0-200 ppm range, no setup or adjustment required
1/4" Quick Connect
Standard John Guest-style fittings for easy inline installation, also available in 3/8" or 1/2" configurations
AC Powered
110V/220V compatible with 24.75" cable, no batteries to replace for reliable continuous monitoring
High Pressure Rated
Handles up to 200 psig water pressure in a compact 5" x 2.9" x 2.4" housing weighing just 12 oz
Universal Water Purification Monitoring
The HM Digital PM-2 works with any reverse osmosis system, deionization filter, or water purification equipment that uses 1/4" tubing. Ideal for monitoring RO permeate quality, DI resin exhaustion, or any application where dissolved solids levels indicate filter performance. Compatible with residential under-sink RO systems, aquarium RODI units, laboratory water purification, and commercial water treatment applications. The external inline design allows installation without cutting into housings or modifying existing equipment.
HM Digital has been manufacturing precision water quality instruments since 1998, trusted by aquarium hobbyists, laboratories, and water treatment professionals worldwide.
