The Maplin Electronic Circuits Handbook, 2nd Edition

220

CIRCUIT CONSTRUCTION

stored

in a

cool place

at a

temperature

of

between

2 C

and

10 C.

Shelf-life

at 20 "C will only

be

around twelve months

and

thus boards should

be

used reasonably promptly after purchase.

Note that

it is not

absolutely essential

to

have access

to an

ultra-violet

light box

as

we

all

have

at

least occasional access

to an

entirely free source

of ultra-violet light. Provided

one is

prepared

to

wait

for a

sunny day

and

prepared

to

experiment

a

little,

the

exposure process

can be

carried

out

in ordinary sunlight.

As a

guide,

and

with

the

full

sun

present overhead,

exposure will take around fifteen minutes. Alternatively,

on ...