_
}“
“
,
“
.
‘
,
‘
“
_
.
_
_
.J
J ,J
_
JJJ,J
'
'
Ï
,
Thermostäts
’
59
.
Thus, the maximum permissable load at
(mains voltage) and 1A 5 .
(thermostat rating) is 240W. Some spare capacity is best
?
_
and so a practical rating of 200W is obtained.
.
_
;;
Any loading above the maximum value .induces severe arcing and
,
produces heat inside the thermostat, which shortens
life and
_
affects its reliability. Small neon indicator lamps are often fitted«
and require some understanding. Usually on separate immersible
thermostats the neon is on when the heater is off and on_èxternal
-
types it is on when the heater is on.
ln combined heater-thermostats
of the immersible type, the lamp is on when the heater is on.-This
situation is confusing and the aquarist should ascertain from the
maker’s specification which type he has obtained. Neons in immersed “_
thermostats can be frightening to nervous fishes, especially in the
ï
dark.
__
_
_
With careful use a thermostat should last several years. Signs of
deterioration are erratic temperature control, often coupled with a
varying differential. If arcing is taking place at the contacts they
_
may require
cleaning, although if they are badly pitted
'
replacement is essential. Neon indicators which flicker several times
‘at each switch—over indicate that the contacts are not closing properly. ; '
When the temperature setting is being adjusted to a new value it is
better to make several small steps rather than one big one,
order
to allow the water enough time to respond and achieve the new “temp—*
_
erat_ure before further adjustments are made. Large Sudden thernioë
j__
»
stat adjustments can cauSe untold trouble, especiallywheh fish—eg 'arÏe‘
—
present in the‘water. External thermostats Can be boxed in if they
are likely to be {affected by draughts or ihterferired with by
-—
or knocked about during hoùsekeeping. This pr0visÏion also
their temperature relationship with the water. —
_
'
_
Thermometers and TemperdÏure—Con‘trol
'
.
—
ft:
…
;
A ,thermometer* is required to“indicate the water temperature and E
"
often a
is benèficial
a—-large aquarium where differenCesï—
from one area to another might exist. ‘Experi‘ment’is worthwhilètb
establish the, position where the instrumeritwill show—the average
«
accuracy is not needed,'nor a,fast
the «imihersible spirit—in-glass type is
paper scale! inside°the
External thermomet‘ers look
:
but-:theif reliability is not ‘usu‘allyas great, and
:
ih=glasstypes are‘unne—cessarily accurate and'_more
a hurry. A
should—be
against“;
_—
one of known accuracy…
before use émdrejected if the reading is more
_
}“
“
,
“
.
‘
,
‘
“
_
.
_
_
.J
J ,J
_
JJJ,J
'
'
Ï
,
Thermostäts
’
59
.
Thus, the maximum permissable load at
(mains voltage) and 1A 5 .
(thermostat rating) is 240W. Some spare capacity is best
?
_
and so a practical rating of 200W is obtained.
.
_
;;
Any loading above the maximum value .induces severe arcing and
,
produces heat inside the thermostat, which shortens
life and
_
affects its reliability. Small neon indicator lamps are often fitted«
and require some understanding. Usually on separate immersible
thermostats the neon is on when the heater is off and on_èxternal
-
types it is on when the heater is on.
ln combined heater-thermostats
of the immersible type, the lamp is on when the heater is on.-This
situation is confusing and the aquarist should ascertain from the
maker’s specification which type he has obtained. Neons in immersed “_
thermostats can be frightening to nervous fishes, especially in the
ï
dark.
__
_
_
With careful use a thermostat should last several years. Signs of
deterioration are erratic temperature control, often coupled with a
varying differential. If arcing is taking place at the contacts they
_
may require
cleaning, although if they are badly pitted
'
replacement is essential. Neon indicators which flicker several times
‘at each switch—over indicate that the contacts are not closing properly. ; '
When the temperature setting is being adjusted to a new value it is
better to make several small steps rather than one big one,
order
to allow the water enough time to respond and achieve the new “temp—*
_
erat_ure before further adjustments are made. Large Sudden thernioë
j__
»
stat adjustments can cauSe untold trouble, especiallywheh fish—eg 'arÏe‘
—
present in the‘water. External thermostats Can be boxed in if they
are likely to be {affected by draughts or ihterferired with by
-—
or knocked about during hoùsekeeping. This pr0visÏion also
their temperature relationship with the water. —
_
'
_
Thermometers and TemperdÏure—Con‘trol
'
.
—
ft:
…
;
A ,thermometer* is required to“indicate the water temperature and E
"
often a
is benèficial
a—-large aquarium where differenCesï—
from one area to another might exist. ‘Experi‘ment’is worthwhilètb
establish the, position where the instrumeritwill show—the average
«
accuracy is not needed,'nor a,fast
the «imihersible spirit—in-glass type is
paper scale! inside°the
External thermomet‘ers look
:
but-:theif reliability is not ‘usu‘allyas great, and
:
ih=glasstypes are‘unne—cessarily accurate and'_more
a hurry. A
should—be
against“;
_—
one of known accuracy…
before use émdrejected if the reading is more
_