HP 3478A Technical Manual Download

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TM 11-6625-3071-14

SECTION I

GENERAL INFORMATION

The information in this manual is for the use of Service
Trained Personnel. To avoid electrical shock, do not
perform any procedures in the manual or do any
servicing to the 3478A unless you are qualified to do so.

1-1.

INTRODUCTION

1-2.

The information in this manual is for the Install

tion, Operation, Performance, Calibration, and Service of
the 3478A Digital Multimeter. The manual is designed for
the use of Service Trained Personnel. Other use should
refer to the Operators Manual. This manual separated
into the following sections.

1-3. Section I, General Information

1-4.

A short description of the manual and

introduction to the 3478A is in Section 1. The section
also lists instrument options, specifications, and
accessories.

1-5.

Section II, Installation Procedures

1-6.

This section explains how the 3478A is prepare

for use and includes power requirements, line voltage
selection, etc. The section also explains how to connect
the multimeter for remote operation.

1-7.

Section III, Operation

1-8.

The condensed operating instructions of 3478A,

for the use of Service Trained Personnel, is this section.
For more complete instructions, refer to Operators
Manual.

1-9.

Section IV, Performance Test and Calibration

1-10.

The 3478A’s Performance Test and Calibration

Procedures are in Section IV. The Required Equipment
Table and an abbreviated specification table are also
included.
1-11.

Section V, Replaceable Parts

1-12.

Section V lists the replaceable parts of the 3478t

It also includes pictures and illustrations of chassis and
mechanical parts.

1-13.

Section VI, Backdating

1-14.

This section has information which adapts this

manual to 3478A’s with serial numbers below the ones
shown on the title page.

1-15.

Section VII, Service

1-16.

The 3478A’s Troubleshooting Procedures,

Theory Of Operation, and Schematics are in Section VII.
The troubleshooting information is in the form of Service
Groups which are symptoms oriented (i.e., what is the
failure). The complete theory of operation is in Service
Group F and the Schematics are in Service Group G
(last group).

1-17.

Appendix A

1-18.

The appendix has a condensed description of

the HP-IB (Hewlett-Packard Interface Bus).

1-19.

DESCRIPTION

1-20. The -hp- Model 3478A is a versatile multimeter
with dc and ac volts, dc and ac currents, and resistance
measurement capabilities. The multimeter is excellent for
bench use, and since it is remotely programmable, it can
be used in measurement systems. A feature of the
instrument is that the reading can be displayed in either 5
1/2, 4 1/2, or 3 1/2 digits. Other features are Autozero
(for good stability), and an Alphanumeric Liquid Crystal
Display.

1-21.

Another excellent feature is Electronic

Calibration. No mechanical adjustments are necessary to
calibrate the 3478A.

1-22.

SPECIFICATIONS

1-23.

Specifications of the 3478A are the performance

characteristics of the multimeter which are certified. The
specifications are listed in Table 1-1 and Table 4-1 (in
Section IV). They are the performance standards or
limits against which the multimeter can be tested.

1-24.

INSTRUMENTANDMANUAL IDENTIFICATION

1-25.

Instrument Identification is by a serial number

located on the multimeter’s rear panel. Hewlett-Packard
uses a two-part serial number, with the first part (prefix)
identifying a series of instruments and the

1-1