photovolt ph meter

[joem]

hi people
I now own 6 used photovolt ph meters model 115
I did not buy these for scrap but to add to my teaching class on PH
( and one for me) but , unkown to me, they did not come with probes.
Does anyone know where I could get replacement probes for these units.
In a way I hope one is non functional so I could see what's inside.

edit : for clarity

 

[qst42know]

Just a guess but they list a Photovolt connector at the bottom of this page.

http://www.geneq.com/catalog/en/ph_orp_electrodes.html