OTF 5000/HS/LS-001/2/3/4 Iss 4 June 2012
10
2.1.5 CHAMBER TEMPERATURE
FIG 7
To set the chamber temperature, press and release the Set button
and then press the Up or Down buttons until the desired
temperature is set. After 5 seconds the actual chamber
temperature will show.
To view the Set temperature, press and release the Set button.
WARNING
: Do not hold the Set button down for more than six
seconds as the control will go into a diagnostic/calibration mode. If the diagnostic/calibration
mode is selected in error take the following steps:
a If Up or Down have not been pressed (i.e. no new parameters have been entered), simply
leave for 20 seconds. Display will revert to normal.
b If new parameters have been selected contact Bright Instrument Co Ltd or your local
representative for advice.
Temperature Alarm
The chamber temperature controller also features an alarm setting which is audible and
connected to an Alarm LED (shown in Fig 5). The Alarm setting is pre-set at the factory.
The alarm function warns the operator if there is a significant deviation from the set chamber
temperature, so that corrective action can be taken
– See Trouble Shooting below.
The controller is factory set with a 2ºC control differential, an 8ºC High Alarm setting and a 20ºC
Low Alarm setting. This means it operates in the following way:
The alarm (light and audible) will activate if the working chambers warms up 8ºC more than the
set chamber temperature or if the chamber temperature goes 20ºC colder than the set
temperature. The Alarm can be manually reset by pressing any one of the 3 Controller buttons
on the Chamber Temperature Controller shown in Fig 7.
On start up, the Alarm is deactivated for 3 hours to allow the cryostat reach its set chamber
temperature. It will then automatically become activated.
During ‘Defrost’ the power to the Controllers is switched off. When defrost is complete the power
will be switched back on to the controllers. Please note that the Alarm will revert back to start up
status and will not become active for 3 hours.
Trouble Shooting
The Alarm may sound in the following conditions:
- If continual work is carried out for long periods with the window open & hands in the
chamber (particularly at low temperature setting), the chamber may warm enough to set
the alarm off
- If the temperature has been reset by more than 8ºC (High Alarm setting) or less than 20ºC
(Low Alarm setting), the alarm will sound until the temperature is within the range.
- Placing a warm microtome in a cold chamber could also cause the alarm to activate.
The correct action to follow is:
-
Reset the Alarm as detailed above
-
Close the window and see if the chamber temperature cools down
-
If it does then continue working
If the chamber continues to warm there is a strong possibility of a fault, call your service
engineer
If the unit returns to its correct operating temperature it could be that the Alarm parameters
need to be adjusted to suit your working conditions. If required contact your service engineer for
instructions.
Summary of Contents for OTF 5000
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