Help with Sparmax Arism Viz compressor

From what I read, the Sparmax Arism Viz compressor is designed for people who needs to use an airbrush when travelling to model show. Low power is essential when operating on battery. 15 psi pressure should be sufficient for most cases, but marginal at times.

If you need a better compressor for home use, the Sparmax TC-2000 is a much better choice and cheaper than your portable compressor too.

I use a Paasche DA-400 compressor with a DIY one gallon airtank. I can use a wide range of airflow rate and the pressure gauge reading does not change more than 0.5 psi. The pressure is adjustable between 10 to 50 psi and holds steady. 

http://cs.finescale.com/fsm/tools_techniques_and_reference_materials/f/18/t/117469.aspx

Just notice that you are in UK. You can get the European made compressor at a much better deal.

Revell Master Class Compressor is one of the top of the class compressor for modelling.