Sartorius SIGMA 3-18 and 3-18K
Sartorius · Model SIGMA 3-18 and 3-18K
SIGMA 3-18 • Universal table top centrifuge; speed range up to 16.000 rpm. • Operation with various fix-angle and swing-out rotors available. • Maximum capacity of 4 x 250 ml down to microtubes with different adapters in the same bucket. • Maintenance-free induction drive motor. A microcontroller controls speed, time, temperature and gravitational field. • 10 quadratic and 10 linear preset deceleration and acceleration curves. Any curve can freely be programmed and displayed grafically. • Suitable for low speeds e.g. for cell sedimentation, accuracy +/– 1 rpm. • Magnetic rotor identification prevents the rotor from overspeeding. • Stainless steel bowl. • Imbalance switch. • Produced according to national and international safety regulations. • Motorized lid lock SIGMA 3-18 K • Technically largely identical to 3-18 but with built-in refrigeration system. • Suitable for low speeds e.g. for all sedimentation. • Higher speed for faster separations. • Possibility of precooling the rotors during standstill. • Refrigerated CFC-free (R 134 a). • Suitable for sedimentation of temperature sensitive substances.
Key tips
- ·Run QC controls before trusting any repair - an analyzer that passes self-test can still report clinically wrong results.
- ·Rule out a reagent lot change before opening the instrument - it can look exactly like a hardware fault.
- ·Centrifuge rotors have a hard retirement age/cycle limit regardless of visible condition - don't eyeball it.
Typical Failure Modes
Failure patterns typical of this equipment class - general BMET reference, not verified against this exact unit's own service history unless flagged. Severity is a category-level estimate.
Sample probe / pipette clog
MediumSymptoms: Aspiration error, short sample, carryover.
Root cause: Clot/crystal obstruction.
Centrifuge imbalance / bearing
HighSymptoms: Vibration, loud noise, stop error.
Root cause: Worn bearing or unbalanced rotor.
Reagent / wash flow fault
MediumSymptoms: Clogs, high blank, QC fail.
Root cause: Pump tube wear, air in line.
Temperature control fault
MediumSymptoms: Incubator out of range.
Root cause: Failed heater/fan or sensor.
Serviceable Parts & Consumables
The parts a BMET typically services on this class of equipment. Service class and relative cost are general engineering estimates for the category, not figures from this unit's documentation. Part numbers appear only when pulled from this unit's own service manual. Always confirm intervals and pricing against the manufacturer.
Peristaltic pump tubing
Consumable, replace proactively.
Class Frequent wear itemRel. cost $R&R Easy
Xenon / LED light source
Class Periodic replacementRel. cost $$$R&R Moderate
Centrifuge rotor & bearings
Class Major service partRel. cost $$$R&R Difficult
Incubator heater / fan
Class Periodic replacementRel. cost $$R&R Moderate
| Part | Service class | Relative cost | R&R difficulty |
|---|---|---|---|
| Peristaltic pump tubing Consumable, replace proactively. | Frequent wear item | $ | Easy |
| Xenon / LED light source | Periodic replacement | $$$ | Moderate |
| Centrifuge rotor & bearings | Major service part | $$$ | Difficult |
| Incubator heater / fan | Periodic replacement | $$ | Moderate |
Relative cost: $ lowest · $$$$ highest service-part cost for this equipment class. Not a price.
PM Checklist
Preventive-maintenance tasks typical of this equipment class. Perform to the manufacturer's procedure and your facility's policy - this is general reference, not a schedule for this specific unit.
- ·Daily QC controls run and reviewed
- ·Calibration verification per assay
- ·Routine cleaning and decontamination
- ·Scheduled reagent-path and pump-tubing maintenance
Troubleshooting Approach
A structured starting point derived from the failure modes above. Follow the manufacturer's service documentation for the actual procedure.
Symptom: Sample probe / pipette clog
- Confirm the presentation - typically aspiration error, short sample, carryover - and note the exact alarm or message and the conditions when it occurs.
- Check the most likely cause first: clot/crystal obstruction.
- Isolate the affected subsystem using the manufacturer's functional check or self-test, where one is provided.
- If the fault is confirmed and not a field adjustment, service or replace the sample aspiration probe per the manufacturer's service documentation.
- Return the device to service only after the manufacturer's functional and applicable electrical-safety checks pass.
- Record the findings, any parts used, and the verification results in the maintenance history.
Symptom: Reagent / wash flow fault
- Confirm the presentation - typically clogs, high blank, QC fail - and note the exact alarm or message and the conditions when it occurs.
- Check the most likely cause first: pump tube wear, air in line.
- Isolate the affected subsystem using the manufacturer's functional check or self-test, where one is provided.
- If the fault is confirmed and not a field adjustment, service or replace the peristaltic pump tubing per the manufacturer's service documentation.
- Return the device to service only after the manufacturer's functional and applicable electrical-safety checks pass.
- Record the findings, any parts used, and the verification results in the maintenance history.
Typical Location
Where this class of equipment is typically deployed - general reference, not this unit's own placement record.
- Central / core laboratory
- Point-of-care testing stations
- Blood bank
- Microbiology lab
Documents & Manuals
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