S 1125 — Isocratic & Low-Pressure Gradient HPLC Pump
The S 1125 HPLC pump system is an exceptionally flexible and powerful solvent delivery platform. Available as the S 1125 isocratic pump or as the S 1125G quaternary gradient pump with optional integrated vacuum degasser. A high-performance stepper motor combined with intelligent motor management delivers extremely high resolution across the full dynamic flow range. The dual-piston design with electronic pressure compensation achieves minimal pulsation for all HPLC and GPC applications.
Dual-Piston Design
Electronic pressure compensation combined with precision dual-piston delivery — minimal pulsation for all HPLC and GPC applications across the full flow range.
Stepper Motor
High-performance stepper motor with intelligent motor management for extremely high dynamic flow range resolution.
Robustness
Sealed, permanently lubricated drive mechanism for long service life with minimal maintenance.
Active Piston Back-Flush (Option)
Pump heads are pre-configured for automatic active piston back-flushing — available without additional drive, and retrofittable to older systems.
S 1125G Quaternary Gradient
Active low-pressure gradient mixer with adjustable mixing volume (10–500 µl). Four channels with 0–100% mixing in 0.1% steps. Optional integrated vacuum degasser removes dissolved gases from primary eluents.
Parameter
Micro
Value
Flow Rate
0.001 – 4.000
Flow Accuracy
± 1.0%
Flow Precision
± 0.1% RSD
Max Pressure
0–400 bar (6000 PSI)
Pressure Pulsation
< 0.1 MPa or < 1.0%
Materials
SS or PEEK
Dimensions (W×H×D)
310 × 165 × 478 mm
Power Supply
100–250 V AC, 47–63 Hz
Vacuum Degasser (optional)
< 20% dissolved gases remaining in water @ 1.000 ml/min
Mixing Range
0.0–100.0%, 4 channels
Mixing Accuracy
< 0.50%
Gradient Mixer
Active
Mixer Volume
Adjustable: 10–500 µl