Integrity of cell monolayer - (Nov/24/2013 )

Hi, 

I have a cell line and I need to check the integrity of the cell monolayer. In order to do that I need to measure transepithelial electrical resistance (TEER). Millipore has a device (Volt-ohm meter) to measure it but it is very expensive: http://www.millipore.com/catalogue/module/c77976

Does anybody know where could I get a second-hand epithelial Volt-ohm meter?

any website to get second-hand scientific devices?

Thank you.

SG 

Labx.com used to do this sort of stuff.