Spare Tyre Pressure

I've got a standard 197 alloy as a spare - I want to check/top up the pressure of it as I am going on a long road trip. What pressure should it be whilst off the car? Due to the weight of the car normally I would presume it to be different to normal?
 
Would just keep it at the standard 32/34.just depends what the tyre says. No need to pump it up should the need to use it arises :smile: hopefully not tho!