SX721 Portable pH/ORP Meter

The Apera Instruments SX721 is a robust and reliable portable meter for pH and ORP (oxidation-reduction potential) measurements, delivering laboratory-grade precision in both indoor and outdoor environments. Designed for general water solution testing, its IP57-rated water and dust resistance, compact build, and durable carrying case make it ideal for use in fieldwork, even under harsh conditions.

This meter includes the 201T-S pH/temperature electrode, which offers fast and accurate readings thanks to its lithium glass membrane and ceramic diaphragm. An integrated thermistor allows temperature measurement and compensation during pH readings. The 301Pt-S ORP electrode features a high-quality platinum sensor for precise redox measurements. It is maintenance-friendly and requires no calibration.

With its digital filtering technology, the SX721 enhances measurement stability and speed. It supports 1–3 point pH calibration and stores up to 200 data sets for easy reference, making it a perfect tool for water treatment, aquaculture, environmental monitoring, beverage production, groundwater testing, and more.

Key Features

• Accurate, fast measurement of pH, ORP, and temperature
• 201T-S pH electrode with lithium glass membrane and temperature compensation
• 301Pt-S ORP electrode with durable platinum sensor, no calibration needed
• Quick 1–3 point pH calibration
• Digital filtering enhances response and accuracy
• 200 data memory capacity for storage and retrieval
• IP57-rated for water and dust resistance
• Rugged and compact—built for the field
• 3-year meter warranty (6 months for electrodes)
• Comes in a complete, ready-to-use kit

Complete Kit Includes

SX721 pH/ORP meter

201T-S pH/temp. electrode

301Pt-S ORP electrode

pH calibration solutions (4.00, 7.00, 10.01 – 50 ml each)

222 mV ORP calibration solution

User manual

2x AA batteries

Screwdriver

Rugged carrying case