Bob Ammerman wrote:
> I have a  requirement for a very high insulation resistance (IR) using so=
me =

> reed relays. We have the relays in hand, and they test at 10e12 or better =

> ohms when open.
> =

> Anybody have any idea what we could expect for IR if mounted on a circuit =

> board. Assume a clearance of about 3/8" between leads.
> =


One site gives (for FR4)
Insulation Resistance	=

Condition: 96 hrs., 90% relative humidity, 95=B0F
  megohms 200,000

But, like the other poster, I would not rely on pcb material but use =

insulated standoffs.  I used to repair lab quality DVMs (at the factory) =

and on some early (1964) instruments leakage was a problem - sometimes =

even requiring hacksaw mods to a production unit.
Later models did not rely on FR4 for insulation in the high impedance =

input circuits.

Geo


-- =

http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist