Portable pH/ORP Meter PH-221 (CAT#: STEM-OEM-0268-ZJF)

The Portable pH Meter is a high-precision instrument designed for accurate measurement of pH and oxidation-reduction potential (ORP) in various liquid solutions. Its compact design and reliable performance make it suitable for on-site water quality analysis, laboratory research, and industrial monitoring.
Accessories include: pH electrode, temperature probe, pH buffer solutions (pH 4.01 / 7.00 / 10.01), and a carrying case.

pH
- Range: -2.000~20.000 pH
- Accuracy: ±0.002 pH
- Resolution: 0.1, 0.01, 0.001 pH, selectable
- Calibration Points: 1 to 5 points
- pH Buffer Options:
USA (pH 1.68/4.01/7.00/10.01/12.45),
NIST (pH 1.68/4.01/6.86/9.18/12.45),
DIN (pH 1.09/4.65/6.79/9.23/12.75),
or 2 custom buffers
ORP
- Range: -1999.9~1999.9 mV
- Accuracy: ±0.2 mV
- Resolution: 0.1, 1 mV, selectable
- Calibration Points: 1 point
Temperature
- Range: 0~105°C / 32~221°F
- Accuracy: ±0.5°C / ±0.9°F
- Resolution: 0.1°C / 0.1°F
- Offset Calibration: 1 point, reading ±10°C
- Temperature Compensation: 0~100°C, manual or automatic
Other Specifications
- Stability Criteria: Low or high
- Calibration Due Alarm: 1 to 31 days or off
- Slope/Offset Display: Yes
- Hold Function: Manual or auto-endpoint
- Auto-Off: 10, 20, or 30 minutes after last key press
- Memory: 500 data sets
- Communication Interface: USB
- Connector: BNC, 3.5 mm jack socket
- Display: Custom LCD (80×60 mm)
- Power Requirements: 3×1.5V AA batteries or DC5V power adapter
- Battery Life: Approx. 150 hours (backlight off)
- Dimensions (W×D×H): 170×85×30 mm
- Package Size: 475×155×350 mm
- Net Weight: 300 g
- Gross Weight: 2 kg

1 to 3 points calibration with automatic recognition for USA and NIST buffers.
Automatic electrode diagnosis helps determine if the pH electrode needs replacement.
Automatic temperature compensation ensures accurate readings across the entire range.
Auto-Read function detects and locks the measurement endpoint.
Setup menu allows configuration of pH buffer set, calibration points, temperature unit, auto-power off, etc.
Reset function restores all settings to factory defaults.
Memory stores or recalls up to 100 data sets.
USB communication interface supports data transfer or external power connection.

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