Lovibond TC 140 G Mode D'emploi page 12

Adjustment and operation
The unit is switched on and off via the On/Off switch.
The „Up" key is used to increase the temperature
The „Down" key is used to decrease the temperature
Setting the temperature values
When the unit is switched on, the display will initially show briefly
the type of oven and a version number. It will then display the
preset temperature, together with the symbol for the specified
figure (3 horizontal lines). After 5 seconds, this will be replaced by
the current, actual temperature.
The unit is preset in the factory to a working temperature of 20 °C.
If this is required to be 25 °C, for example:
Press the „⬆" key once. The display will show the specified figure
which has been set, together with the symbol for the specified
figure (3 horizontal lines). Now press the „⬆" key again, or
hold it down until the display shows the new figure required
(25 °C in this example). Then release the key. The display will show
the new setting for 5 seconds and will then display the actual,
current temperature.
If a lower working temperature is required, the same procedure
applies, using the „⬇︎" key. The temperature can be adjusted in
steps of 0.1 °C between 2 °C and 40 °C.
If you wish to read the specified temperature but without changing
it, simply press the „⬆" or „⬇︎" key once and release it, so that the
display shows the specified figure instead of the current temperature.
The specified figure cannot be changed unless one of the keys is
pressed while the display is already showing the specified figure.
The preset temperature will not be lost if there is a power failure
of if the unit is switched off. The data are stored in an internal
electronic memory and are called up automatically when power is
restored or the unit is switched on.
12
The illustration shows the actual
temperature of 20.0 °C.
Detecting a power failure
When the unit is first switched on, the display will flash. Pressing
the „⬆" or „⬇︎" key will cause it to stop flashing and remain per-
manently lit.
If there is a power failure, the display will start to flash again. This may
indicate that the temperature in the oven can no longer be held at
the working temperature, if the power is off for an extended period.
The controls will continue to operate normally, even if the display
is flashing. The flashing merely indicates that the unit has been
switched off and then back on again, or that the power supply
failed for a time and no key has been pressed since then.
It is important to note that the display will flash, even if the power
supply has failed for a very short period. It does not necessarily
mean that the temperature in the oven has deviated significantly
from the specified level.
Temperature control and accuracy
The thermostatically controlled incubators are not specified accor-
ding ASTM E 145 (9-point-measurement) or DIN 12880, part 2
(27-point-measurement).
Specifications are based on a one-point-measurement.
Test procedure
1. Place a sample bottle filled with 500 ml water with a stirring
rod on a stirring place and place it in the middle of a grid (5th
insert from the bottom).
2. Completely immerse the probe of the meter in the water sample
(according to the specifications of the meter). The probe should
not touch the bottle wall.
Specifications of the meter:
3. The temperature is read after 4 hours.
Trouble shooting
If the verification of the temperature accuracy is not successful the
following should be taken under consideration:
- The ambient temperature of the thermostatically controlled
incubator must match the climate rate (type plate).
- A certain circulation of air is necessary for the compressor to
work properly.
- The incubator should not be opened to often and / or for longer
period of time.
- Check the function of the two fans by visual inspection.
- Check the cooling device by setting 10 °C and wait for a signi-
ficant change of the temperature in the sample towards 10 °C.
- Check the heating device by setting 40 °C and wait for a signi-
ficant change of the temperature in the sample towards 40 °C.
- Depending on the sample temperature it can take up to 7 hours
for temperature stability at the set-value.
Important
The air temperature in the cabinet may fluctuate by several degrees
centigrade. Nevertheless the actual temperature of the sample
fluctuates only by a maximum of ± 0.5 °C.
Other operation controls
On the front side of the temperature control unit there are
covered shock-proof sockets for the connection of BOD's
appliances or stirring apparates. The total load on the sockets
must not exceed 4,5 amps.
The thermostatically controlled oven and laboratory sockets are
protected by a fuse (6.3 A T) which is accessible from the front
panel of the unit.
The control unit is connected by means of a 4-pole plug on the
bottom of the incubator.
Accuracy at least 0.5°C
Resolution at least 0.1°C
TC 140 G / TC 256 G_1 04/2014