pH Pen Meters

Economy pH Pen Meter

Economy pH Pen Meter

Model: MA-257
Price: $61.00
Standard pH Pen Meter

Standard pH Pen Meter

Model: MA-258
Price: $104.00

Ohaus Pen pH meters provide accurate readings and a straightforward operation at an affordable price. A ph tester is useful in the field or lab for soil classification and other applications measuring pH or relative acidity or alkalinity of a sample at a given temperature. These meters have a pH measurement range from 0 to 14pH. The working environment for both units is 50°F to 104°F (10°C to 40°C) and 85%RH, non-condensing.

The pocket-size meters display readings on a large, easy-to-read digital LCD display. These digital pH meters endure prolonged environments and are constructed with durable ABS housing. They also feature an IP67 waterproof design to prevent water damage.

A protective cap to safeguard the sensor and a wrist strap is included. Meters have an automatic shutdown feature that preserves battery life. The waterproof ph meters operate for approximately 200 hours on four included AG13 button-cell batteries.

MA-257 has a range of 0–14pH, 0.1pH resolution, and accuracy of ±0.1pH. The built-in electrode is factory calibrated with no need for use of Buffer Solution. It features a single-line LCD display.

MA-258 has a range is 0–14pH, resolution is 0.01pH, and ±0.05pH accuracy. It also has temperature compensation with a range of 0–99.0°C (32.0 to 210.2°F). The built-in electrode features a 3-point calibration using 4.01, 7.00, and 10.01 Buffer Solution (sold separately). The dual-line LCD screen displays pH and temperature values.


  • Easy-to-read display
  • ABS housing
  • Automatic shutdown feature preserves battery life
  • IP67 waterproof design
  • Battery-powered

Included Items:

  • Economy or Standard pH Pen Meter
  • Four AG13 button-cell batteries
  • Wrist Strap


  • Buffer Solutions are a calibration solution for calibrating ph pen meter (MA-258 model only)
Power Supply Four AG13 button-cell batteries
Product Dimensions 1.8 x 7.3 x 1.5in (45 x 185 x 38mm) WxDxH
Estimated Shipping Weight 2.0lb (0.91kg)

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Power Supply Four AG13 button-cell batteries
Product Dimensions 1.8 x 7.3 x 1.5in (45 x 185 x 38mm) WxDxH
Estimated Shipping Weight 2.0lb (0.91kg)
Meets Standard(s):
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