The ESR analyser unit checks the vacuum built up in a pipette just before Sampling. A vacuum stabilization error will occur if it takes too long to evacuate a pipette or vacuum level is not stable.

Vacuum stabilization error may caused by:

1. Leakage in sample tube connecting mixing-piece and fill nozzle.
   • Replace the silicone sample tube.
2. Fill block washer defective or not in place.
   • Needs replacement, fatal error.
3. Leaking O-ring in the fill nozzle, replace the fill nozzle O-ring.
4. Sample tube pinch valve (next to fill nozzle) not operating.
   • Needs replacement, fatal error.
5. Wet or dirty blue air filter on flow-sensor board, replace blue air filter
6. Defective flow sensor board.
   • Needs replacement, fatal error.
7. Outer needle valve is not functioning correctly and vacuum is leaking away, check outer needle valve.