Hanna Combo pH/Conductivity/TDS Tester (Low Range)

The HI98129 makes measuring pH quick and easy! This lightweight, waterproof tester offers high accuracy pH, low range EC/TDS (0 to 3999 µS/cm EC/ 0 to 2000 ppm TDS), and temperature measurements in a single handheld unit!

No more switching between meters for your routine measurements. The HI98129 is a highly accurate, waterproof pH meter that can also measure EC/TDS in the low range (0 to 3999 µS/cm EC/ 0 to 2000 ppm TDS) and temperature. This floating, waterproof combination tester has an easy to read, LCD and an automatic shut-off. In addition, pH and EC/TDS readings are automatically temperatures compensated (ATC) to prevent temperature-related variations in your measurements. For EC/TDS readings, the EC/TDS conversion factor (CONV) is selectable by the user, as well as the temperature compensation coefficient β (BETA).

Replaceable pH Electrode Cartridge

The HI98129 tester features an easy-to-replace pH electrode cartridge with an extendable cloth junction. The extendable cloth junction helps increase electrode life and the replaceable pH cartridge means that this tester does not need to be thrown away when the pH sensor is exhausted. Also, the sturdy, snap-in connector means there are no pins to bend or break!

High Accuracy EC/TDS Graphite Probe

The graphite conductivity probe provides greater accuracy because it cannot be contaminated by salt deposits in the solution. The exposed temperature sensor provides fast response times and guarantees highly accurate temperature compensated readings.

Features at-a-glance

Q&A

What is a combo pH, conductivity, and TDS tester?

A combo pH/conductivity/TDS tester is a handheld multi‑parameter meter that measures the acidity/alkalinity (pH), electrical conductivity (EC), total dissolved solids (TDS), and often temperature of water or liquid solutions—all from one instrument. This eliminates the need to use separate meters for each parameter and simplifies routine water quality testing. 

Why measure pH, conductivity and TDS together?

These three parameters together provide a comprehensive picture of water quality: pH shows the acidity/alkalinity, conductivity indicates the ability of water to conduct electrical current based on dissolved ions, and TDS estimates the total amount of dissolved solids—all of which are important in environmental monitoring, hydroponics, aquariums, pools, and general water testing.

How does the meter measure conductivity and TDS?

Conductivity is measured by applying an electrical signal between electrodes in contact with the sample; the higher the ion concentration, the higher the conductivity. TDS is then calculated from the conductivity reading using a conversion factor that can often be adjusted to match different solution types. 

Do these testers compensate for temperature?

Yes. Most combo testers include automatic temperature compensation (ATC), which adjusts conductivity and TDS readings based on sample temperature, since conductivity varies with temperature. 

What typical ranges can these meters measure?

Common combo testers measure pH from about 0.00 to 14.00, EC from low microsiemens up to several millisiemens/cm (varying by model), and TDS from 0 up to thousands of parts per million (ppm). Higher‑range models can measure more concentrated solutions. 

Are these meters waterproof and portable?

Many combo pH/EC/TDS testers are designed to be waterproof and even float if dropped in water, making them suitable for field use and on‑site testing without special accessories. 

How accurate are combo testers?

Accuracy varies by model, but these meters typically provide sufficiently accurate results for general water quality assessment and routine testing, with pH resolution around 0.01, EC and TDS accuracy depending on the sensors and calibration method used. 

What calibration is needed?

pH calibration is usually performed with standard buffer solutions, while conductivity/TDS calibration often uses known conductivity standards. Many models support automatic or semi‑automatic calibration to maintain measurement accuracy. 

Examples of combo testers you might consider:

• **:contentReference[oaicite:8]{index=8}** – A well‑reviewed multi‑parameter meter combining pH, conductivity and TDS testing.
• **:contentReference[oaicite:9]{index=9}** – Waterproof combo meter for field testing.
• **:contentReference[oaicite:10]{index=10}** – Low‑range version ideal for natural waters and drinking water quality checks.
• **:contentReference[oaicite:11]{index=11}** – Higher‑end combo meter with robust build and quality sensors.
• **:contentReference[oaicite:12]{index=12}** – Budget‑friendly combo meter commonly used for hydroponics and general water quality.
• **:contentReference[oaicite:13]{index=13}** – Compact and waterproof tester including temperature measurement.
• **:contentReference[oaicite:14]{index=14}** – Highly rated combo meter with easy‑to‑read display.
• **:contentReference[oaicite:15]{index=15}** – Multi‑parameter tester including conductivity and TDS among other features.