What do these products do in this instrument?
Tubing and fittings: connect sources, metering units and probe tips
Connect bottles, metering units, valves and probes while preserving the intended sample-contact and system-liquid boundaries. Tubing used to drive a sample at the probe has a different contact duty from tubing that carries the specimen itself; that distinction determines materials, cleaning and recovery checks.
Tubing and fittings together form sealed connections and the actual transfer path. Check formulation, inner/outer diameters, length, tube-end positioning and port geometry, including added volume in residue and arrival delay.
Separate specimen contact from system-liquid displacement
Draw the path in each aspiration and delivery state before choosing materials or bore. In a system-liquid architecture, verify the interface that separates the specimen from the driving liquid; in a direct-contact path, include the entire specimen-wetted section in the wash sequence. Reducing internal volume can reduce liquid held between operations, but the selected bore and routing must still support aspiration, probe motion and service access.
Further technical reading
Treat a connection change as a change to the delivery sequence
Record the installed tube length, bore and port seating when a line or fitting is replaced. Added volume can alter priming and the time at which fresh reagent reaches the probe; a gap can retain an earlier composition. Recheck the first transfer and the sample-change sequence, not only the absence of visible leakage, before restoring the original program.
Translate actual branch conditions into configuration requirements
| Condition | To confirm |
|---|---|
| Contact map | Mark specimen, reagent, system-liquid and wash contact for each segment, including the cleaning agents and actual contact conditions. |
| Installed dimensions | Record the length and bore that determine held liquid, together with tube outer diameter, end position, fitting seal and mating port. |
| Return to service | Define the priming outlet and first-dose check, then assess the relevant high-to-low sample sequence or reagent blank after a connection change. |
| Operation | Specific operating conditions |
|---|---|
| Tubing connections | Actual specimen-contact or system-liquid layout, reagent and wash formulations, installed tube dimensions, port seating and the transfer sequence after service |
Tubing connections
Start at the liquid source and follow the active path through the valve, metering unit and probe. Label where the specimen is retained and which sections contain driving or wash liquid; this determines what a connection change can affect.
When replacing a line, restore the intended routing and port seating before changing the dosing program. Measure priming and the first received transfer so an assembly difference is not hidden by a software correction.
Assess aspiration and delivery pressure states with the actual assembly, including movement of the probe where relevant. Check that routing remains seated and does not kink during the programmed motion.
If volume recovers but the next sample or blank remains affected, investigate retained liquid and washing at the changed interface. Volume calibration and removal of previous composition solve different problems.
Compare product configurations by the roles on this page
| Product | Configuration option | Conditions to verify |
|---|---|---|
| Tubing materials and dimensions | Connection paths and shared volume | Bore, length, load and actual formulation jointly determine materials and dimensions |
| Rigid-tubing fittings | Tube-end positioning and sealed connections | Check tube outer diameter, threads, seal structure and port-bottom geometry |
Related operations and architecture comparisons
Sample aspiration and transfer
Low remaining volume, probe contact with a wall and aspiration/dispensing reversals may alter delivery. First measure error in the target container, then assess residue using a blank after a concentrated sample; one calibration cannot address both issues.
Metered reagent dispensing
For repeated dispensing, record usable doses per fill and replenishment points. Confirm restoration of the liquid column after replenishment before evaluating the first dose. Retrying an interrupted action must also avoid duplicate addition to the same cuvette.
Probe/cuvette wash supply and waste removal
Internal-probe, external-probe and cuvette-bottom residue cannot all be solved by increasing the same supply volume. Check cleaning coverage, aspiration height and waste capacity, then validate recovery with high/low concentration switching and blanks.
Confirm product roles in actual operation
| Operation | Measurements and observations | Priority checks |
|---|---|---|
| Tubing connections | Compare cuvette receipt and first-dose arrival before and after the connection change. Include idle recovery and the relevant high-to-low sequence with the complete probe-wash procedure. | A leak test may pass while extra length, a seating gap or retained wash liquid changes the first transfer. Inspect the changed segment before compensating with a different pump command. |
Keep an installation record that can reproduce the accepted path. Release it after sealing, actual delivery and the relevant carryover or blank checks agree with the analyzer method.
Is a replacement tube acceptable when the threads fit and the line does not leak?
Also compare bore, installed length, tube-end seating and the wetted seal. Those changes can alter held liquid and first-dose behavior without an external leak, so verify the actual transfer and sample-change sequence after replacement.
The assay determines sample suitability; full-scale metering specifications cannot replace small-dose and complete-instrument results.