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1
Brief Instruction
Thank you for choosing Apera Instruments SX721 Portable pH/ORP Meter (will be called “the meter” in
short in the following content). Before using the meter, please read this instruction manual carefully in
order to help you properly use and maintain it.
The meter can measure the parameters of pH, ORP, and temperature of water solutions with high
accuracy. It is suitable for various applications in different industries e.g., water treatment, aquaculture,
horticulture, pools and spas, beverage making, mining, power plants, environmental monitoring, etc.,
especially ideal for in-field use.
The meter has the following features:
1.1.
Built-in microprocessor chip with the intelligent functions of auto. calibration, auto. temperature
compensation, auto. salinity compensation, manual baromatric pressure compensation, data storage,
function settings, auto. power off, and low voltage display etc.
1.2. Adopts digital filter technology to intelligently improve meter’s response speed and accuracy. The
smiley face icon will appear when the reading is stable.
1.3. Pure water modes available for pH, significantly increasing the accuracy in pure water measurement.
1.4. Meter’s LCD screen has clear and bright backlit display.
1.5. Built-tough. IP57 waterproof and dust-proof.
2
Technical Specifications
2.1
pH
Measurement range
(-2.00 to 19.99) pH
Resolution
0.1/0.01 pH
Accuracy
Meter: ±0.01pH; Overall: ±0.02pH
Input current
≤2×10
-12
A
Input impendance
≥1×1012 Ω
Stability
±0.01 pH/3h
Temp. compensation range
(0 to 100) °C (automatic)