HP 2373A, E2377A, and E2378A The HP E2300 Series of handheld multimeters is ideal for portable Choice of auto-ranging or manual range hold. Digital multimeter E2378A Equipment Hewlett-Packard, HP; Palo Alto, CA, build 1990 ??, 4 pictures, United States of America , schematics, tubes. hp. HEWLETT. PACKARD. SERVICE MANUAL. MODEL 3478A. DIGITAL MULTIMETER. Serial Numbers: This manual applies directly to in-.Part Number: E2377-90001 (Feb89). This user's guide is provided for information only. The E2377A and E2378A are no longer sold by Keysight. This manual may contain references to HP or Hewlett-Packard. Please note that Hewlett- E2377A/E2378A Handheld Multimeter User's Guide. E2377-90001. The E2378A is a 3.5 digit handheld multimeter from Agilent. A multimeter is an instrument used to test and measure alternating current (AC) or direct