pH electrode compatible with TRIS - (Aug/04/2011 )

Hi.
We recently realized that the pH probes we frequently destroy may not be compatible with TRIS. Actually good brands like Mettler Toledo has it as an option like "TRIS compatible probes".
Could anyone suggest the properties of such a probe? I digged out some information on the web, such as it should be free of AgCl, it shouldn't be single junction (or is this old information)...
We currently use Jenco 6173 benchtop ph meter, if I can get a clue of what to look for, we will contact the company to buy a new probe.
Any help is appreciated.

Best wishes to everyone

instead of agcl the tris compatible electrode uses hgcl

and the fill solution should not contain agcl either