Unstable He value / Flow Limiter High Flow
Flow limiter incorrect flow impacts mostly He reading - unstable or not measuring at all. But O2 readings can be affected as well, expecially with pure oxygen.
Possible causes:
- Damaged flow limiter
- Wrong flow rate setting
- Damaged or failing helium sensor assembly
Step-by-step troubleshooting:
- Check flow rate with flowmeter (or a glass full of water, there should be steady stream of bubbles, not a geyser), in numbers the flow should be 0.2-0.5 L/min.
- Simple flow limiter's flow can be adjusted by turning the nozzle
- Proffesional flow limiter cannot be adjusted, only closed or fully opened to release residual pressure
- Inspect flow limiter for damage or modifications
- Ensure steady, continuous flow during measurement
- If your helium value stays unstable even after disconnecting the tubing from Flow limiter to Analyzer, the Analyzer requires further helium assembly troubleshooting, search for "internal values" and / or re-calibration procedure.
When to contact service: If flow cannot be regulated properly, or helium value stays unstable even after all troubleshooting steps.