yew didn't say weather you ware looking at a e.s.p. 1 oar 2.
hear's a manual fore the 1. knot shore the difference with the 2.
http://qsl.net/k0ff/01%20Manuals/Eberline/ESP-1/ESP-1%20Eberline%20Smart%20Portable%20Technical%20Manual1.pdf
that sayed, e.s.p. models aren't my favs. their heavy and cumbersome. iffen yins use the smart cabling, they get two delicate fore my field usage. my usage level is probly a bit moor robust than yores, as I will typically take 50-250 static measurements with scan activity mixed inn per day. esp meters take a little getting used too in regards two switching modes.
the IC, EPROM & CMOS components have shelf life and bleed off issues,...
the transformers and voltage dividers are sketchy after three to five years,...
these are 25 year old plus units,...
old digital is broke mick digital,...
if you want digital do yourself a favor and buy a primary unit less than five years old,...
and that will only have a couple of reliable years left,...
even the E600 line (which was once upon a time my favorite) is too old too muck with,...
you're actually better off with old analogs than old digitals,...
keep in mind that analogs are just that, they're analog,...
digitals use TWA circuitry, et al, to appear analog to the user since we process information that way under specific circumstances,...
so that small digital input problems become large end user output problems and the end user is clueless,...
now,....
new, off the shelf, software interfacing, telemetrically plugged in digital wizard stuff?!?!?!?
it's scintillating,...makes you say stupid small words like "WOW!",...
it also costs a bunch,...
stay analog my friend, it's more predictable and garage shelf friendly for less money,...
unless you own an EPROM burner and have access to a Texas Semiconductor catalogue,...
and a high four low five figure hobby bank account,...