AD-12 pH meter

AD-12 pH meter

ADWA AD-12: a digital pocket pH tester with 0.01 pH resolution

The AD-12 pH meter is a digital pocket meter for accurate measurement of the pH of water and other liquids. It shows pH to two decimal places and the sample temperature at the same time, with automatic temperature compensation. Price: €49.90. The set includes pH 4.01 and 7.01 calibration solutions with a certificate, an electrode storage solution (10 mL) and instructions in Slovenian.

According to the official ADWA manufacturer's instructions it measures in the range from −2.00 to 16.00 pH and temperature from −5 to 60 °C.

AD-12 pH meter

How it works and how to calibrate it

Switch the meter on, dip the electrode into the sample, stir gently and wait for the value to settle. The main display shows the temperature-compensated pH and the second shows the sample temperature. Rinse the electrode between samples so that the samples do not mix.

Calibration is automatic: the meter recognises the buffer by itself. For accurate measurements choose two-point calibration: first the 7.01 buffer (or 6.86), then 4.01 or 10.01 (or 9.18). When the meter accepts the first point it shows OK 1, and after the second point OK 2. Calibrate at least once a month, after replacing the electrode, after measuring aggressive chemicals, or whenever you need higher accuracy.

You can also watch the procedure in the video on two-point calibration.

Advantages: AD-12 pH meter

• Pocket size, easy to use
• pH shown to two decimal places (resolution 0.01 pH)
• Range −2.00 to 16.00 pH
• Automatic temperature compensation and temperature display
• Automatic calibration with buffer recognition, 1 or 2 points
• Replaceable AD11P electrode
• Batteries last about 300 hours of use
• Automatic switch-off after 8 minutes
• The set includes calibration solutions with a certificate and a storage solution
• Price: €49.90

Use: AD-12 pH meter

Who is it for

Choose it for measuring the pH of water and other liquids where the second decimal matters. If one decimal is enough, see the AD-11 pH meter, and for pH and ORP measurements the AD14 pH/ORP meter. For fieldwork or professional laboratory measurements there is the AD111 professional portable meter.

Maintenance: AD-12 pH meter

Storing and cleaning the electrode

Store the electrode in its protective cap with a few drops of storage solution, never in distilled water. Rinse it with water after use, clean it once a month with an electrode cleaning solution and recalibrate. If the electrode dries out, soak it in the storage solution for at least one hour. The replacement electrode is the AD11P. More on maintenance in the video on storing the electrode.

Technical specifications: AD-12 pH meter

• pH range: −2.00 to 16.00
• Resolution: 0.01 pH
• Accuracy: ±0.01 pH at 25 °C
• Temperature: −5.0 to 60.0 °C (resolution 0.1 °C, accuracy ±0.5 °C)
• Calibration: automatic, 1 or 2 points, buffers 4.01/7.01/10.01 or 4.01/6.86/9.18
• Temperature compensation: automatic
• Electrode: AD11P, replaceable
• Power supply: 4 × 1.5 V batteries, about 300 hours
• Dimensions: 175.5 × 39 × 23 mm, weight 100 g
• Automatic switch-off: after 8 minutes

If you are looking for an AD-12 pH meter for accurate measurement of water pH to two decimals, this is a pocket ADWA tester with automatic calibration. Also see all ADWA pH and ORP meters.