Water Quality & pH Test Instruments — Pen Type pH Meter Series

AMT28 & AMT28F Pen Type pH Meters

Keywords: pen type pH meter, portable pH tester, digital pH meter, skin pH meter, flat surface pH tester

No-Calibration pH Testing — AMT28 for Liquids, AMT28F for Flat Surfaces.

The AMT28 series offers portable, pen-type pH meters designed for fast, everyday pH checks without routine calibration. Both models cover the full 0.00–14.00 pH range with 0.01 pH resolution and automatic temperature display. Choose the AMT28 with a glass electrode for liquid samples, or the AMT28F with a flat sensor for testing skin, fruits and other flat surfaces.

Operation is simple: activate the meter, wait for the reading to stabilize, and the value is held automatically. A one-key factory reset restores accuracy after months of use, while the compact pen design and three LR44 batteries make it easy to carry and use anywhere.

Key Features

1.  No Calibration Needed — Ready to use under normal conditions; factory reset is available if accuracy drifts.

2.  Two Sensor Types — AMT28 for liquid, AMT28F flat sensor for skin, fruits and flat surfaces.

3.  Full pH Range — Measures 0.00–14.00 pH with 0.01 pH resolution.

4.  Automatic Hold — Reading is held automatically once stable, with temperature shown alternately.

5.  One-Key Factory Reset — Long-press to restore default calibration in about 15 seconds.

6.  Portable Pen Design — Lightweight 173 mm body fits in a pocket for field or lab use.

How to Use

1.  Activate the Sensor — For first use or after long storage, turn the meter off and soak the sensor in sample liquid or tap water (not distilled water) for 2–5 minutes; shake gently. For AMT28F, spray a little water on a dry surface before testing.

2.  Power On — Long-press the ON/OFF button; the meter displays pH and temperature alternately.

3.  Take the Reading — Wait for the value to stabilize; the reading is held automatically. Short-press ON/OFF to retest.

4.  Power Off — Long-press ON/OFF to shut down.

5.  Factory Reset (if needed) — With the meter off, long-press ON/OFF for about 15 seconds until "dEFA" appears, then release.

6.  Clean After Use — Rinse the sensor with tap water and check the battery compartment for moisture.

Model Overview

Technical Specifications

Applications

1.  Drinking water, swimming pools and aquariums

2.  Hydroponics and gardening

3.  Food & beverage quality checks

4.  Skin and cosmetic pH testing

5.  Fruits, cheese, meat and other flat food surfaces