Marconi TF 933C - Chapter 2 OPERATION; Installation; Controls and Connections

To Next Page

To Previous Page

Chapter

Operation

2.1

INSTALLATION

NOTE

The

performance

of this

instrument

may

impaired

lengthy

exposure

damp

atmosphere.

Drying

for a

short

period

warm

dry

atmosphere

will

restore

it to

give

normal

performance.

Ensure

that

the

instrument

switched

OFF

before

connecting

any

leads

and

only

switched

when

actually

taking

measurements,

hence

prolonging

the

life

the

batteries.

2.2

CONTROLS

AND

CONNECTIONS

Balance controls

The electrical

principle employed in the instrument is the variation of

conductivity

of the specimen with moisture

content. Conductivity

is measured by adjusting the

coarse and fine BALANCE controls to give a standard meter indication; the

reading on

the controls

is then easily converted

into moisture

content by

reference to the scale on

the

instrument or to a chart supplied with

it.

addition to

the two BALANCE controls there

rotary switch marked OFF-

ZERO-READ

and a red ZERO knob for standardizing

the instrument before taking

measurement.

NOTE:

either

of the

BALANCE

controls becomes

loose

must not be

secured

without

first

carrying out the

standardization test detailed

in Sect. 4.2.

Electrode

connections

•me

compression cell electrode

is normally stowed in the lower

front

compart—

of the

moisture

meter. Also

inside this

compartmelt

are

three sockets

labelled

RED,

GREEN

and

BLACK.

Connect the

RED and BLACK sockets on the

93.w

Marconi TF 933C - Chapter 2 OPERATION; Installation; Controls and Connections

Table of Contents