DATA PRECISION 1350 User Manual

62-5008 MODEL 1350
Chapter 3
CALIBRATION
CAUTION
Dangerous line voltages are exposed when the cover Is
removed. Take extreme cautions when examining circuit in
vicinity of the fuse and line switch.
3.1 GENERAL
Each Model 1350 DMM has been calibrated at the factory before ship
ment and is designed to provide accurate stable performance within
specifications for at least one year. When recalibration is required, the
procedure, as described in this chapter, is extremely simple. Model 1350
DMM has been designed with precision stable components so that only
three (3) calibrating adjustments are required to bring Model 1350 DMM
within specified performance.
The calibration, to be done by qualified personnel only requires: (1) that
the timing circuit that programs the dual-slope integrating A/D converter
be driven by an accurately adjusted oscillator to assure maximum re
jection of power-supply-correlated noise; (2) that the reference be
adjusted for accurate voltage measurement; and, (3) that positive and
negative inputs will be measured with equal accuracy. Other measure
ments will then be within tolerances.
3.2 CALIBRATION ADJUSTMENTS
a. The three (3) calibration adjustments, R7, R15, and R38 are accessi
ble when the top cover of the instrument is removed. Their locations are
identified in Figure 3-1, and their reference symbol designators are
screened on the main pc-board assembly.
b. To remove the top cover,
(1) Disconnect ac power source
(2) Remove the two upper fastening screws in the rear panel assembly
(Figure 2-2, Item 1)
(3) Raise the top cover, disengaging the dowel from the front alignment
hole, and remove the cover.
■^Copyright 1977. Data Precision Corporation. AM rights reserved.
3-1

DATA PRECISION 1350 Specifications

General

Brand	DATA PRECISION
Model	1350
Category	Multimeter
Language	English