FOREACH 250 μL Miniature Precision Ceramic Piston Pump for Reagent Dispensing and Metered Reaction-Liquid Addition, with a PMMA Pump Head
SM-250-PMMA is a 250 μL miniature precision piston pump with a PMMA head for reagent dispensing and metered reaction-liquid addition. Designed for integration into small automated instruments and sampling mechanisms, it supports 1/4-28 UNF or M6 ports and 2000 full-stroke steps. Full-stroke repeatability is ≤0.5% under the specified conditions.
SM head options include PMMA, PSU, POM and PEEK; piston options include ceramic, stainless steel and PEEK. Optical sensors, valves, probes, tubing and a controller can be matched to the project. Materials and mounting are selected for the fluid and instrument.
Typical Applications:
Analyzer reagent dispensing, Metered reaction-liquid addition, Automated sampling and sample dilution, Water-analysis reagent metering
| Volume | 250 μL |
|---|---|
| Displayed pump head material | Poly(methyl methacrylate) (PMMA) |
| Pump head material options | PMMA / PSU / POM / PEEK; final selection follows fluid and structural requirements. |
| Piston material options | Ceramic / stainless steel / PEEK; select with the seal and fluid. |
| Fluidic interface | 1/4-28 UNF / M6 |
| Stroke | 12.7 mm |
| Recommended max speed | 600 RPM |
| Motor step angle | 1.8° |
| Lead | 1.27 mm |
| Full-stroke steps | 2000 Step |
| Accuracy at 100% stroke | Confirm for the selected configuration and working volume |
| Repeatability at 100% stroke | ≤0.5% (specified full-stroke conditions) |
| Repeatability at 2% stroke | Confirm for the selected configuration and working volume |
| Backlash | < 1.0% |
| Designed life | 5 million cycles (pure water, room temperature, 50 kPa back pressure) |
| Max fluid pressure | <0.30 MPa |
SM-250-PMMA applications and selection requirements
SM miniature piston pumps can be configured for clinical chemistry, immunoassay, laboratory automation, sample preparation, life science instruments and water or environmental analysis. Depending on the fluidic task, selection may focus on a reagent dispensing pump, sampling pump, sample dilution pump, reaction-liquid dispensing pump, buffer dosing pump or standard-addition pump.
SM-250-PMMA focuses on reagent dispensing and metered reaction-liquid addition. Select the 250 μL capacity against the working dose. If the total transfer exceeds one stroke, include refill and valve-switching time. The displayed configuration uses a PMMA head and ceramic piston. All wetted materials must be checked against the actual fluid.
Clinical chemistry and immunoassay: reagent dispensing pump
Analyzers repeatedly add programmed reagent doses to reaction units. Selection depends on consistency at the working dose and coordination between the pump, selector valve and dispensing probe.
SM-250-PMMA: Aspiration and dispense strokes can be coordinated with reagent-routing valves; wetted materials are selected against reagent composition, temperature and cleaning conditions. SM supports integration with automated sampling mechanisms; 2000 full-stroke steps provide position control for aspiration and dispensing. Full-stroke repeatability does not establish performance at smaller doses.
Life science instruments: metered reaction-liquid dispensing pump
Small-volume reaction systems add different liquids in sequence. Important requirements include dose error, residual droplets, carryover and space for valves and detection components.
SM-250-PMMA: Capacity, step count and control timing support staged dosing, with valves and outlet geometry matched to the instrument. Droplet retention and carryover must be tested in the complete fluid path. Select the 250 μL capacity against the working dose. If the total transfer exceeds one stroke, include refill and valve-switching time.
Laboratory automation: sampling and sample dilution pump
Automated sampling and sample preparation require separate control of sample and diluent volumes, together with management of carryover, bubbles and valve timing.
SM-250-PMMA: The pump can be configured with probes, tubing and valves for sampling and dispensing. Dilution-ratio performance also requires validation of sample volume, diluent volume and mixing. Select the 250 μL capacity against the working dose. If the total transfer exceeds one stroke, include refill and valve-switching time.
Water and environmental analysis: reagent metering and standard-addition pump
Small water-analysis modules add defined reagent or standard volumes to measurement cells. Selection depends on the dosing range, fluid chemistry, concentration and maintenance conditions.
SM-250-PMMA: Dose capacity and fluid-path switching can be matched to the measurement sequence. The head, piston, seals and valves must be assessed together; corrosive, particulate or crystallization-prone fluids require specific validation. Select the 250 μL capacity against the working dose. If the total transfer exceeds one stroke, include refill and valve-switching time. The displayed configuration uses a PMMA head and ceramic piston. All wetted materials must be checked against the actual fluid.
Confirm the working conditions
Provide dose volume, allowed error, timing, fluid composition, temperature, back pressure and mounting space. 250 μL divided by 2000 steps gives approximately 0.125 μL per step as a nominal calculation only. Validate minimum reliable dose, carryover and dripping in the complete fluid path.
The SM specification gives an expected life of five million cycles with pure water at room temperature and 50 kPa back pressure. Saline or crystallization-prone fluids require shutdown flushing and maintenance planning.
Frequently Asked Questions
It focuses on reagent dispensing and metered reaction-liquid addition. Related selection tasks include analyzer reagent dispensing, metered reaction-liquid addition, automated sampling and sample dilution, water-analysis reagent metering. Select the 250 μL capacity against the working dose. If the total transfer exceeds one stroke, include refill and valve-switching time.
Piston Pump Configured for Your Instrument
Share the target volume, fluid compatibility, port type, control method, installation space, and service-life requirements. The FOREACH engineering team can help confirm the pump configuration and wetted materials.