Datron 1061 - Page 11

197 pages

Save Page as PDF

To Next Page

To Next Page

To Previous Page

To Previous Page

Loading...

4

1.3

OHMS

CALIBRATION

1.3.1

General

The

procedure

in

the

table

opposite

is

all

that

is

necessary

to

completely

'AUTOCAL'

the

Ohms

function'

lf

just

the

Ohms

or

just

one

range

of

the

Ohms

is

to be

calibrated, then

steps

1

and

2

in the

DC

Voltage

Calibration

table

should

be

carried

out first. Then

on

each

Ohms

range

just

a

'Zero'

and 'Gain'

calibration

ís

required.

lf the

'DVM

Reading

After

Calibration'

is not

in

accordance

with

the table,

repeat

operations

of

the

same

'CALIBRATE'

key

is

permissible

to

improve

the

reading'

Where no tolerance

is

shown in this

column,

only

the

exact

reading

quoted

with

an occasional

least

significant

digit

showing

is

to be

expected.

1.3.2

'Ze¡o'

Resistance

Source

For accurate'Zero'calibration

on

Ohms

it

is

ESSENTIAL

that a correctly

connected

zero source

is

used.

Two

arrangements are

necessary as shown

in

Fig.

1.1;

it

can

be seen that'4

wire Sl'selection is recommended

on

all

ranges.

1.3.3

Equipment Required

A

set of resistance standards

from 10Q

to

1OMQ

in

decades;

it is

essential that 10Q to

100kO

standards

are

4

terminal

devices. e.g. Datron

4000/40004

Autocal

Standard

with Option 20.

1.3.4

Checking

Accuracy after

'AUTOCAL'

To check

the accuracy after

'AUTOCAL'the

'Speci-

fication

Verification'

section

of the

Operating

Handbook

will

be useful.

lt

provides

tables

for

quick

reference

of

accuracy

on all ranges

and functions

in displayed

digits.

ç

1MO

and

lOMn

lOft

1o

1O0kn

I-

Lo

\

_\

I+

Hi

I+

H¡

Fis. 1.1 zERO RESISTANCE

SOURCE

CONNECTIONS

(Local

Guard

)-

O Guard

Guard

O Guard

Guard

Copper

Shorting

Link

(

Local

Guard)-

Lo

I-

Table of Contents