Locate the source, drive and receiving position for this task
Define actual flow, cumulative volume, allowable flow interruptions, backpressure, refills and operating duration. Follow the diagram to confirm liquid contact, pressure and destination before assigning drive and connection roles.
Screen candidates using installed flow and exchange time
Screen displacement and speed using target flow, path volume and allowable exchange time, then check outlet pressure and inlet conditions. Nominal exchange time can be estimated; actual mixing and detector response require measurement.
| Condition to compare | Information required | Selection affected |
|---|---|---|
| Installed flow rate | Target flow, backpressure and inlet conditions | Compare displacement and speed combinations |
| Path refresh | Shared volume, liquid changes and stabilization time | Define when valid measurement can begin |
| Signal requirements | Short-term fluctuation, bubbles and cumulative volume | Define supply variation permitted by the method |
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 |
|---|---|---|
| RPL Valveless Metering Pump | Suitable repeated or continuous metering | Compare displacement, speed, actual backpressure and starts/stops; check two-stream ratios separately |
Record liquid changes and baseline recovery
Prime and remove unintended bubbles before establishing stable supply. Record composition arrival and baseline recovery after carrier changes or restarts. Include load changes from filters, valves and tubing.
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.
Test short-term fluctuations and cumulative volume separately
Measure flow over different time windows, cumulative volume and method baseline, including startup, liquid changes and load changes. For abnormal baselines, investigate bubbles, formulation, flow and detection conditions together.
| Validation scenario | Measurement or observation | Interpretation and action |
|---|---|---|
| Short time windows | Compare flow changes with baseline or response | Relate flow fluctuations to detection anomalies |
| Long-term cumulative volume | Measure cumulative delivery, including liquid changes | Correct cumulative volume still requires separate assessment of steady-state signals |
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
An empty source, bubbles, slip, pressure changes or resets can disturb sustained output. Reconcile undelivered volume and process state before restarting to avoid duplicate additions.
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
- Valveless metering pumps: operating conditions for repeated dispensing and continuous supply
- Repeated Dispensing with Valveless Pumps: Displacement, Start-Stop Behavior and Nozzle Droplets
- Valveless-pump titration: when to use bulk addition and when fine metering is needed
- Dual-Stream Proportioning: Cumulative Ratio and Instantaneous Mixing