Note: This is an advanced functionality NOT an unnecessary, wasteful  extravagance which others would have you believe! We are proud of the evolution of our product and feel for most users this is a solution not a limitation. The consumption of a few cubic liters of gas (typically N₂, Ar or Clean Dry Air) per hour is a small price to pay to insure indefinite trouble-free operation. The purge itself can be disconnected and the interlock disabled after acknowledgement of the dangers and responsibility of doing this.

Another alternative:

In those situation where a gas purge is not possible our previously manufactured "A" model which uses an electro-mechanical vacuum control valve is still available. see What happened to the "A" series? at the top of each model page.