FID

[abdidhere]

please help is it advisable to keep FID off when not in use to save pressurised air cylinders

[Peter Apps]

Flame off, heater on.

[dblux_]

please help is it advisable to keep FID off when not in use to save pressurised air cylinders

Keep it off. You may turn off the electrometer as well. If FID will be used in short time then keep it in slightly elevated temperature. If it won't be used in a couple of days then switch off heating - FID equilibrates quite quickly and there is no need to keep it heated for week or more.