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HM Digital (TDS-4) Handheld Digital TDS Meter-Monitor

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HM Digital (TDS-4) Handheld Digital TDS Meter-Monitor

The HM Digital TDS-4 is a compact handheld meter that measures total dissolved solids from 0 to 9990 ppm with digital precision, ideal for testing RO system performance, aquarium water, hydroponics, and any application where water purity matters. Factory-calibrated and featuring auto-hold, auto-off, and a built-in thermometer, it's the smallest and lightest professional TDS meter available.
SPECIFICATIONS

HM Digital TDS-4 Technical Specs

Measurement Range
0–9990 ppm
Dual range with auto-switching resolution
Resolution
1 ppm / 10 ppm
1 ppm (0–999), 10 ppm (1000–9990)
Calibration
342 ppm NaCl
Factory calibrated, field adjustable
Temperature
0–80°C
Built-in digital thermometer (Celsius)
Auto Functions
Hold & Off
Saves readings; 10-min auto-shutoff
Form Factor
Handheld
Smallest and lightest TDS meter available
TECHNICAL DETAILS

HM Digital TDS-4 Meter Specifications

Model Number TDS-4
Manufacturer HM Digital
Measurement Type Total Dissolved Solids (TDS)
Display Digital LCD with x10 indicator
Power Source Battery operated (included)
Calibration Method Mini-screwdriver adjustment (included)
Accuracy ±2% full scale
COMPATIBILITY & APPLICATIONS

Ideal Uses for the TDS-4 Meter

The HM Digital TDS-4 is designed for all water purification applications including reverse osmosis system testing, drinking water quality assessment, wastewater regulation compliance, aquarium and aquaculture monitoring, hydroponic nutrient solution management, pool and spa water testing, colloidal silver production, and water cooler maintenance. Use it to verify your RO membrane is rejecting contaminants properly (good RO water should read under 50 ppm), test tap water baseline levels, or monitor any application where dissolved solids concentration affects water quality or equipment performance.

💧 Test your tap water first to establish a baseline TDS reading, then test your RO output—you should see a 90–98% reduction if your membrane is working properly. If rejection drops below 85%, it's time to replace your RO membrane.
The HM Digital TDS-4 is a compact handheld meter that measures total dissolved solids from 0 to 9990 ppm with digital precision, ideal for testing RO system performance, aquarium water, hydroponics, and any application where water purity matters. Factory-calibrated and featuring auto-hold, auto-off, and a built-in thermometer, it's the smallest and lightest professional TDS meter available.
SPECIFICATIONS

HM Digital TDS-4 Technical Specs

Measurement Range
0–9990 ppm
Dual range with auto-switching resolution
Resolution
1 ppm / 10 ppm
1 ppm (0–999), 10 ppm (1000–9990)
Calibration
342 ppm NaCl
Factory calibrated, field adjustable
Temperature
0–80°C
Built-in digital thermometer (Celsius)
Auto Functions
Hold & Off
Saves readings; 10-min auto-shutoff
Form Factor
Handheld
Smallest and lightest TDS meter available
TECHNICAL DETAILS

HM Digital TDS-4 Meter Specifications

Model Number TDS-4
Manufacturer HM Digital
Measurement Type Total Dissolved Solids (TDS)
Display Digital LCD with x10 indicator
Power Source Battery operated (included)
Calibration Method Mini-screwdriver adjustment (included)
Accuracy ±2% full scale
COMPATIBILITY & APPLICATIONS

Ideal Uses for the TDS-4 Meter

The HM Digital TDS-4 is designed for all water purification applications including reverse osmosis system testing, drinking water quality assessment, wastewater regulation compliance, aquarium and aquaculture monitoring, hydroponic nutrient solution management, pool and spa water testing, colloidal silver production, and water cooler maintenance. Use it to verify your RO membrane is rejecting contaminants properly (good RO water should read under 50 ppm), test tap water baseline levels, or monitor any application where dissolved solids concentration affects water quality or equipment performance.

💧 Test your tap water first to establish a baseline TDS reading, then test your RO output—you should see a 90–98% reduction if your membrane is working properly. If rejection drops below 85%, it's time to replace your RO membrane.
$10.55

Original: $30.14

-65%
HM Digital (TDS-4) Handheld Digital TDS Meter-Monitor—

$30.14

$10.55

Description

The HM Digital TDS-4 is a compact handheld meter that measures total dissolved solids from 0 to 9990 ppm with digital precision, ideal for testing RO system performance, aquarium water, hydroponics, and any application where water purity matters. Factory-calibrated and featuring auto-hold, auto-off, and a built-in thermometer, it's the smallest and lightest professional TDS meter available.
SPECIFICATIONS

HM Digital TDS-4 Technical Specs

Measurement Range
0–9990 ppm
Dual range with auto-switching resolution
Resolution
1 ppm / 10 ppm
1 ppm (0–999), 10 ppm (1000–9990)
Calibration
342 ppm NaCl
Factory calibrated, field adjustable
Temperature
0–80°C
Built-in digital thermometer (Celsius)
Auto Functions
Hold & Off
Saves readings; 10-min auto-shutoff
Form Factor
Handheld
Smallest and lightest TDS meter available
TECHNICAL DETAILS

HM Digital TDS-4 Meter Specifications

Model Number TDS-4
Manufacturer HM Digital
Measurement Type Total Dissolved Solids (TDS)
Display Digital LCD with x10 indicator
Power Source Battery operated (included)
Calibration Method Mini-screwdriver adjustment (included)
Accuracy ±2% full scale
COMPATIBILITY & APPLICATIONS

Ideal Uses for the TDS-4 Meter

The HM Digital TDS-4 is designed for all water purification applications including reverse osmosis system testing, drinking water quality assessment, wastewater regulation compliance, aquarium and aquaculture monitoring, hydroponic nutrient solution management, pool and spa water testing, colloidal silver production, and water cooler maintenance. Use it to verify your RO membrane is rejecting contaminants properly (good RO water should read under 50 ppm), test tap water baseline levels, or monitor any application where dissolved solids concentration affects water quality or equipment performance.

💧 Test your tap water first to establish a baseline TDS reading, then test your RO output—you should see a 90–98% reduction if your membrane is working properly. If rejection drops below 85%, it's time to replace your RO membrane.