Temperature
Range for Control
The normal full range of control for each of the temperature controllers
is -55 °C to +105 °C ± 0.02 °C. If one specifies the
extended temperature version available for the TLC 40, TLC 42, or TLC 50
(place a
/E after the model number), then the full control range is -55 °C up
to +150 °C ± 0.02 °C.
| approximate
temperatures achievable under various conditions |
TLC
40 |
TLC
42 |
TLC
50 |
CD
250 |
TURRET
400 |
FLASH
200 |
FLASH
300 |
LC
600 |
| highest temperature
/E option |
150 |
150 |
150 |
-- |
-- |
-- |
-- |
-- |
| normal highest
temperature |
105 |
105 |
105 |
105 |
105 |
105 |
105 |
105 |
| in the open,
no dry gas flow |
5 |
5 |
5 |
5 |
5 |
5 |
5 |
5 |
| exposed but
with dry gas flow |
-10 |
-10 |
-10 |
-10 |
-10 |
-10 |
-10 |
-10 |
| enclosed in
dry environment, 0 degree circulating fluid |
-25 |
-25 |
-25 |
-25 |
-25 |
-25 |
-25 |
-25 |
| with windows,
cold circulating fluid, some added insulation |
-40 |
-40 |
-40 |
-40 |
-- |
-40 |
-40 |
-- |
| with windows,
very cold circulating fluid, lots of added insulation |
-55 |
-55 |
-55 |
-- |
-- |
-55 |
-55 |
-- |
Achievable temperatures:
| • |
highest
temperature /E option – Special versions of the TLC
40, TLC 42, or TLC 50 can be made to operate
above 105 °C. This requires special firmware in the microcomputer
of the temperature controller and special changes that replace
or isolate heat sensitive components under the cuvette. Temperatures
up to 150 °C may be obtained, although the upper range
of temperatures should not be used for extended periods of
time.
Operation substantially above boiling temperatures requires
shutting down the cooling fluid circulation, limiting some
features of control. |
| • |
normal
highest temperature – All sample holders will heat
to at least 105 °C. Unless the extended temperature option
is installed, the controller limits operation to this
temperature to prevent damage to internal components. |
| • |
in
the open, no dry gas flow – Unless special care
is taken, operation at or below the dew point temperature
of the room (estimated here to be 5 °C) will result in
condensation on the cuvette windows. |
| • |
exposed
but with dry gas flow – Most cuvette holders are
provided with a dry gas purge option that greatly limits
condensation when working in an exposed environment,
permitting operation down to about -10 °C. |
| • |
enclosed
in dry environment, 0 degree circulating fluid – When
used inside of a spectrophotometer that can be purged
with dry gas, no condensation will occur, and much lower
temperatures may be reached. For a sample holder mounted
in a spectrometer, simply providing dry gas flow to the
holder will satisfactorily prevent condensation. Ice
water is a convenient circulating fluid for most low
temperature work. |
| • |
with
windows, cold circulating fluid, some added insulation – Very
cold operation requires the use of optical windows to thermally
insulate the cuvette. We recommend the windowed jackets
WJ-40, WJ-50 and WJ-200 on the TLC 40, TLC 50 and FLASH
200, respectively for this purpose. The CD 250 can also
be provided
with
windows that mount directly on the sample
holder. Very low temperatures also require the use chilled
cooling fluid to remove heat from the Peltier unit. Typically
one uses methanol or methanol-water mixtures within about
25 °C of the temperature you wish to achieve. Any additional
insulation provided by the user (such as a layer of bubble
wrap, for example) can speed temperature equilibration. |
| • |
with
windows, very cold circulating fluid, lots of added insulation – We
have only tested our sample holders down to -40 °C, but
lower temperatures can be achieved with special care. Please
contact us for suggestions on how to work at these very
low temperatures. |
Probe Temperature Range
The TC 125 and TC 425 temperature controllers accept standard 400 and
500 Series thermistor probes. These probes may be obtained from Yellow
Springs
Instrument Company (ysi.com) or Cole Parmer (coleparmer.com). Standard
400 Series temperature probes will measure the temperature within ±0.1
°C over the range of 0.0 to 70.0 °C. The probe will operate over the
full range of -55 °C to +105 °C, but an individual probe will need to
be calibrated
by the user outside of the 0.0 to 70.0 °C range. The 500 Series probes
are less standardized and will require calibration by the user. 500 Series
probes may be convenient, because they are available in very small diameters.
|