It's used to test the level of liquid

>From: "abdelyamine" 
>Reply-To: General MEMS discussion 
>To: "'General MEMS discussion'" 
>Subject: [mems-talk] purge with N2
>Date:Wed, 3 Jan 2007 13:40:03 +0100
>
>Hello
>
> I've found on flow diagram of my equipment (Spray Acid Tool), that the tanks
> of chemicals (H2SO4, HF.) are purged with N2. Could anyone tell me why,
> please!!