Hi, Wayne. You can get your operating manual tomorrow for $40 USD plus
shipping from Manuals Plus. I've dealt with them several times, and
found them to be very helpful.
Speaking from some experience, the time and effort to either try to
figger out an instrument like this or scrounge the manual are never
worth it. Better just to buy it. Manuals are irreplaceable for using
complex instruments well.
http://www.manualsplus.com/
Manufacturer: AGILENT(HP)
Model: 4275A
Description: OP
Part Number: 04275-90004
Condition: Reprint
Price: $40.00
Call Toll-Free: 1-800-345-4019
International: 1-801-936-7000
Fax: 801-936-7004
Manuals Plus
130 N. Cutler Drive
North Salt Lake, Utah 84054 U.S.A.
It's a good meter. By the way, HP didn't make this one themselves. I
don't believe HP/Agilent has provided any significant support for this
meter for at least 5 years. If you're looking for the manual because
you're considering buying, caveat emptor.