Locate the source, drive and receiving position for this task
Required inputs are dose per operation, total cycle volume, replenishment/bottle-change interval, backpressure and receiving geometry. Confirm liquid contact, pressure and destination along the diagram before assigning drive and connection responsibilities.
Provide suitable stroke for routine doses and maximum task volumes
List minimum, routine and maximum doses separately, and calculate path filling, retained volume and replenishment frequency. Larger capacity can reduce replenishment but does not automatically improve small-dose performance. Smaller capacity increases the stroke fraction used for routine doses but may lengthen cycles for larger tasks. Compare EA, SM and TM configurations under actual installation and operating conditions.
| Condition to compare | Information required | Selection affected |
|---|---|---|
| Routine small doses | Minimum, routine and maximum delivered volumes | Compare usable stroke and working-point calibration |
| Cycle capacity | Total displacement before replenishment, auxiliary actions and retained volume | Determine capacity and refill timing |
| Wetted configuration | Direct sample contact or system-liquid separation | Check materials and interface management |
Compare product options against task requirements
The following candidate options match this page's responsibilities. Compare them against the operating conditions described, then check capacity, materials and interfaces on the product pages. Card images show representative configurations; suitability must still be confirmed at actual operating points and by application results.
| Product category | Corresponding role | Confirm before selection |
|---|---|---|
| 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 |
Distinguish system-liquid-separated cycles from direct-contact cycles
Confirm source, valve position, priming, aspiration, delivery and cleaning in sequence. When system liquid isolates the sample, the sample may not enter the pump head. In direct-contact designs, include the head, seals and all shared sections in material and cleaning assessment. A pump command does not detect aspiration of air.
Action records should link commands, valve or interface states and actual received results. When raw material, container or sample identity changes, reconfirm shared paths and conditions permitting the next step. Completion of drive movement alone does not replace task acceptance.
Measure short-stroke, first-dose and reversal behavior at the receiver
Measure bias and repeatability at the receiver for actual working doses, including the first dose after idle, direction reversal, bottle changes and actual liquids. If analytical results are abnormal, investigate delivery, carryover and method conditions separately. Full-stroke specifications cannot be extrapolated directly to minimum doses.
| Validation scenario | Measurement or observation | Interpretation and action |
|---|---|---|
| Short strokes and reversal | Measure different working volumes at the receiving position | Distinguish consistent bias from action-dependent variation |
| Standby and replenishment | Compare the first dose after restart with subsequent doses | Check the liquid column, sealing and supply before adjusting compensation |
Record test medium, configuration, installed path and operating sequence; present routine operating points and boundary results separately. Calculations support design discussions, component documentation checks models, and installed measurements confirm the actual task.
After an abnormality or maintenance, first identify which segment needs recovery
Empty sources, bubbles, nozzle droplets and backpressure changes can affect first or last doses. Stop affected steps, validate recovery after priming and avoid duplicate dispensing.
Retain current source, container identity, completed actions, valve or interface state and actual receiving information. Use the table to locate the stage that changed before deciding to retry, continue or restart. After recovery, recheck the relevant operating point before returning an uncertain action to the automatic cycle.
Continue with tasks on the same branch
References
View references (11)
- [1]FOREACH: Precision piston-pump configurations
- [2]Hamilton: Microlab 600 Basic Manual, Rev. K
- [3]Ouyang et al. (2008): Strategies to Maintain Sample Integrity Using a Liquid-Filled Automated Liquid-Handling System
- [4]FOREACH: EA Piston Pump Datasheet, PS-120B-2507-00001_001
- [5]FOREACH: EA-100-PEEK specifications
- [6]Hamilton: Microlab 600 Advanced Manual, Rev. E
- [7]FOREACH: EAS Easy-to-Degas Piston Pump Datasheet, PS-120B-2507-00002_001
- [8]Tecan: Liquid handling pump selection — a guide for lab automation engineers
- [9]FOREACH: SM Piston Pump Datasheet, PS-120B-2507-00004_001
- [10]FOREACH: TM-100-PMMA specifications
- [11]Albert & Bradshaw (2007): Importance of Integrating a Volume Verification Method for Liquid Handlers