Handheld Meters


What is TDS?

Total Dissolved Solids (TDS) are the total amount of mobile charged ions, including minerals, salts or metals, dissolved in a given volume of water, and expressed in units of mg per unit volume of water (mg/L), also referred to as parts per million (ppm).


Products


Handheld TDS Meter ZT-2Handheld TDS Meter ZT-2
Part Number: TDS-ZT2
Alternate Part Number: ZT-2
HM Digital ZT-2 Handheld TDS Meter Features:Highly efficient and accurate due to its advanced microprocessor technology. Hold function -- Saves measurements for convenient reading and recording, with the sound of a buzzer. Auto-off function --...View Details
$15.59 

2+ for $14.81 ea
5+ for $14.03 ea
Set of 10 for $13.25 ea
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Handheld TDS Meter EZHandheld TDS Meter EZ
Part Number: TDS-EZ
HM Digital TDS-EZ Handheld TDS Meter Features:Highly efficient and accurate due to its advanced microprocessor technology. Hold function -- Saves measurements for convenient reading and recording, with the sound of a buzzer. Auto-off function --...
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$15.59 

2+ for $14.81 ea
5+ for $14.03 ea
Set of 10 for $13.25 ea
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Handheld TDS Meter 3 w/ ThermometerHandheld TDS Meter 3 w/ Thermometer
Part Number: TDS-3
HM Digital TDS-3 Handheld TDS/Temp Meter Features:Highly efficient and accurate due to its advanced microprocessor technology. Hold function -- Saves measurements for convenient reading and recording, with the sound of a buzzer. Auto-off function...
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$22.20 

2+ for $21.09 ea
5+ for $19.98 ea
Set of 10 for $18.87 ea
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Pocket Size TDS MeterPocket Size TDS Meter
Part Number: TDS-4
HM Digital TDS-4 Handheld TDS/Temp Meter Features:Highly efficient and accurate due to its advanced microprocessor technology Hold Function -- Saves measurements for convenient reading and recording Auto-off function -- Automatically shuts off...
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$21.00 

2+ for $19.95 ea
5+ for $18.90 ea
Set of 10 for $17.85 ea
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Pocket Size TDS Meter w/ ThermometerPocket Size TDS Meter w/ Thermometer
Part Number: TDS-4TM
HM Digital TDS-4TM Handheld TDS/Temp Meter Features:Includes an internal digital thermometer Hold Function -- Saves measurements for convenient reading and recording Auto-off function -- Automatically shuts off meter after 10 minutes of non-use...
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$22.20 

2+ for $21.09 ea
5+ for $19.98 ea
Set of 10 for $18.87 ea
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AquaPro Upscale Consumer TDS/Temp MeterAquaPro Upscale Consumer TDS/Temp Meter
Part Number: HMAP-1
Alternate Part Number: AP-1
  • Measures total dissolved solids (TDS) and temperature
  • Automatic Temperature Compensation (ATC)
  • Water-resistant housing
  • Measurement Range: 0-5000 ppm
  • Display: large and easy-to-read LCD screen
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$25.79 

2+ for $24.50 ea
5+ for $23.21 ea
Set of 10 for $21.92 ea
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Handheld EC & Temp Meter w/ caseHandheld EC & Temp Meter w/ case
Part Number: HMEC-3
Alternate Part Number: EC-3
  • Includes a carrying case with belt clip.
  • Highly efficient and accurate
  • Hold Function
  • Built-in digital thermometer
  • Display: large and easy-to-read LCD screen.
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$22.20 

2+ for $21.09 ea
5+ for $19.98 ea
Set of 10 for $18.87 ea
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AquaPro Upscale Consumer EC/Temp MeterAquaPro Upscale Consumer EC/Temp Meter
Part Number: HMAP-2
Alternate Part Number: AP-2
  • Measures electrical conductivity (EC) and temperature
  • Automatic Temperature Compensation (ATC)
  • Water-resistant housing
  • Measurement Range: 0-9999 µS
  • Display: large and easy-to-read LCD screen
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$25.79 

2+ for $24.50 ea
5+ for $23.21 ea
Set of 10 for $21.92 ea
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EC / TDS / TEMP Combo MeterEC / TDS / TEMP Combo Meter
Part Number: COM-100
HM Digital COM-100 EC/TDS/Temp Combo Meter Features:Measures electrical conductivity (EC), total dissolved solids (TDS) and temperature Three different calibration options (KCl, 442TM, NaCl), each with its own non-linear conversion factor...
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$59.95 

2+ for $56.95 ea
5+ for $53.96 ea
Set of 10 for $50.96 ea
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pH / Temp Meter WaterproofpH / Temp Meter Waterproof
Part Number: PH-200
HM Digital PH-200 Handheld pH/Temp Meter Features:Measures pH and Temperature Auto-ranging three point calibration with digital fine tuning Includes 4 pH buffer solution in a sponge embedded in a clear cap, so you can see if it's dried up...
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$79.95 

2+ for $75.95 ea
5+ for $71.96 ea
Set of 10 for $67.96 ea
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Hanna Instruments pH & ORP Combo MeterHanna Instruments pH & ORP Combo Meter
Part Number: HI98121
  • High accuracy pH and ORP measurements
  • Large dual-level LCD and shuts-off automatically
  • Automatically compensate for the effects of temp
  • Simultaneous pH and ORP measurements
  • Waterproof tester has a greatly extended life
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    $99.00 

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    ORP-200 Waterproof ORP MeterORP-200 Waterproof ORP Meter
    Part Number: ORP-200
    Alternate Part Number: Extech ExStik RE-300
    HM Digital ORP-200 Handheld ORP Meter Features:Measures Oxidation Reduction Potential (Redox) and Temperature Auto-ranging calibration with digital fine tuning Includes 4 pH buffer solution in a sponge embedded in a clear cap, so you can see if...
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    $87.95 

    2+ for $83.55 ea
    5+ for $79.16 ea
    Set of 10 for $74.76 ea
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    Hanna Instruments pH, TDS, EC, and Temp Combo meterHanna Instruments pH, TDS, EC, and Temp Combo meter
    Part Number: HI98129
  • High accuracy pH, EC/TDS and temp measurements
  • Large dual-level LCD and shuts-off automatically
  • Automatically compensate for the effects of temp
  • User can select the EC/TDS conversion factor and the temperature compensation coefficient (ß)
  • Waterproof tester has a greatly extended life
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    $147.99 

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    TM-1 Digital ThermometerTM-1 Digital Thermometer
    Part Number: TM-1
    For use in all hot and cold fluids and/or solids; aquariums; kitchens and bakeries; hydroponics and aquaculture; freezers/coolers and heating systems; motors, generators and ventilations systems; academic, scientific and medical laboratories....
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    $19.95 

    2+ for $18.95 ea
    5+ for $17.96 ea
    Set of 10 for $16.96 ea
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    Button Cell Battery - 1.5V (76A) L1154Button Cell Battery - 1.5V (76A) L1154
    Part Number: L1154
    1.5V battery for TDS-3, TDS-4, TDS-4TM, TM-1, COM-100, & DM-1 Meters. Meters that do not display anything when you press the "ON" button need to have their battery replaced.View Details
    $1.00 

    10+ for $.62 ea
    20+ for $.65 ea
    50+ for $.50 ea

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    How Does a TDS Meter Work

    TDS meters are really conductivity meters. The way a TDS meter works is by applying a voltage between two or more electrodes. By applying this voltage, the negatively charged ions will move towards the positive charged electrode, and positive charged ions towards the negative electrode. The TDS tester monitors the amount of current passing between the two electrodes as a gauge of how many ions are in solution, and allows you to calculate the TDS reading.

    Tips for Using a TDS Meter

    1. Rinse the end of the TDS meter that is being submerged in water with the freshest water that is available. Buildup of salts on the meter will interfere with proper operation, and can skew the readings.
    2. Do not touch the TDS electrode surfaces with hands or abrasive cloth.
    3. To Clean the TDS electrodes, you can soak the tips in vinegar or diluted hydrochloric acid (muriatic acid) and then rinsing well with water. Check your TDS meter handbook for individual cleaning methods.
    4. If you are using a TDS meter to monitor the performance of an RO membrane, then the TDS measured value should decrease by at least a factor of 10 from the starting tap water. For example, if water out of your tap is 231 ppm, then the water from your RO system should be less than 23 ppm. In many instances, a drop of less than a factor of 10 indicates a problem with the RO membrane.

    TDS Meter Comparison Charts


    Complete TDS Meter Comparison Chart
    Model Name

    Temp. Function
    Water Resistant
    Digital Display
    Range ppm(mg/L)
    TDS-ZT2

         0 - 999
    TDS-EZ


    0 - 999
    TDS-III

    0 - 999
    TDS-IV


    0 - 999
    TDS-V
         0 - 999
    HMAP-1
       0 - 5000
    HMEC-3

       0 - 999
    HMAP-2

     0 - 999
    COM-100  0 - 999
    PH-200
    0 - 999
    HI98121


    0 - 999
    ORP-200

    0 - 999
    HI98129
    0 - 999