Yup, another discussion about mercury batteries, but different than I could find in the archives. I don't want to re-start the same old discussion on Wein cells and hearing aid batteries. The best solution to the mercury battery problem is to adjust the meter circuit to use silver oxide bateries. I say this after looking at the curves of voltage verses temperature and current of the series diode solution. The series diode is a "sloppy" solution. I am looking for someone who has adjusted the meter to use silver oxide cells who is willing to share the procedure. I have done camera repairs, CLA and electronics bench work, so I am not afraid to tackle the job, I just don't want to "re-invent the wheel". Thanks.