What do these products do in this instrument?
Piston pumps: whole-blood sampling and reagent metering
Drive sampling or specified reagent volumes in suitable metering architectures, coordinated with sampling probes, sample mixing and low remaining liquid in the source container. Validate sample volume and subsequent dilution ratio separately.
EA, SM and TM provide options for comparing capacity, wetted configurations and installation space. Verify actual doses from working stroke and the complete wetted path; check system-liquid drive and direct sample contact with the pump head separately.
Distinguish piston displacement from actual received volume
Piston pumps use controlled displacement for discrete aspiration and dispensing. Sample may enter the head directly or remain at the probe tip while system liquid transmits displacement; wetted coverage, priming and cleaning differ. Map aspiration, holding, dispensing and replenishment paths first, then relate stroke to probe-tip delivery.
Further technical reading
Combine metering, valve positions and container actions into a complete cycle
Delivery requires coordination of metering drive, source switching and receiving-end actions. Usable capacity must cover working volume and other cycle displacements, with replenishment in permitted windows. Check tip droplets, bubbles and shared residual liquid through the complete path; remeasure received volume after changing pump heads, tubing lengths or interfaces.
Translate actual branch conditions into configuration requirements
| Condition | To confirm |
|---|---|
| Working stroke | Define the whole-blood sampling dose and any reagent task separately, accounting for the usable stroke and replenishment needed by the actual architecture. |
| Liquid contact and pressure | Map the blood-contact or system-liquid path, probe position and pressure states together with sample mixing and the source volume remaining. |
| Delivery and recovery | Check repeated sampling with actual whole-blood conditions, low source volume and probe washing. Verify the delivered sample volume separately from the later dilution ratio. |
| Operation | Specific operating conditions |
|---|---|
| Whole-blood sampling and delivery | Whole-blood condition and mixing, sampling dose, time between repeated aspirations, remaining source volume, probe position and actual metering architecture |
Compare product configurations by the roles on this page
| Product | Configuration option | Conditions to verify |
|---|---|---|
| EA standard piston pump | Finite-stroke metering | Compare configurations by routine dose, total cycle displacement and wetted materials |
| SM miniature piston pump | Discrete metering in compact installations | Check installation space first, then validate working doses and actual accuracy |
| TM ultra-miniature piston pump | Discrete metering in limited space | Check installation space and configuration before measuring actual delivery; an ultra-miniature design does not imply a smaller reliable dose |
Explore specific operating and validation tasks
Whole-blood sampling and delivery
Sample condition may change between repeated aspirations. Compare containers with normal remaining sample volume, low remaining sample volume and particle risks, recording tip position and air-aspiration handling rather than testing only repeated water aspiration/dispensing.
Confirm product roles in actual operation
| Operation | Measurements and observations | Priority checks |
|---|---|---|
| Whole-blood sampling and delivery | Compare received sample volumes through repeated whole-blood sampling at normal and low source levels. Check sample changes and wash recovery, then validate the subsequent dilution ratio separately. | Changes in sample condition, particles or clots, air aspiration, probe-wall contact or leakage can affect sampling. Use the actual sample and channel state when investigating an abnormal result. |
Assess whole-blood sampling and recovery across the complete sample sequence. Metered sample volume, subsequent dilution ratio and detection-channel recovery are separate acceptance results.
Are piston pumps of equal capacity directly interchangeable?
Also check wetted materials, interfaces, mounting, drive and pressure conditions. After replacement, recheck delivery, cleaning and first-dose recovery with the original sequence and actual liquids. Capacity is only one comparison criterion.
Metered dilution and sheath-fluid flow are different roles; sheath-fluid requirements depend on the detection architecture.
References
View references (4)
- [1]FOREACH EA standard piston pump: configurations and specifications
- [2]FOREACH SM miniature piston pump: configurations and specifications
- [3]FOREACH TM ultra-miniature piston pump: configurations and specifications
- [4]Sysmex hematology analyzer reference: impedance and fluorescence flow-cytometry configurations