What is the purpose of the Purge valve on our FISONS EA 1108 and should it remain open during operation and closed during Stand-By? What should be the flow rate for the purge?
The purge valve on that model EA is used exactly as you assumed. During operation it must remain opened in order to keep the sample purged of atmosphere and during stand-by closed to conserve purge gas. The purge flow rate (measured by removing the tubing and fitting from the autosampler) should be about 55 – 60 ml/min. for the AS-200 and about 70 – 80 ml/min. for the AS-128 using helium as the purge.
