Temperature Control
Oven safety
In complex two•or three•rampoven temperature programs, information as to the part of the program in progress is monitored by pressing
OVEN TEMP 
.
Note that, during a ramp, the SETPOINT value displayed is that calculated to be the correct temperature, based upon specified heating/cooling rate, and initial and final oven temperatures.
Also, note that if the RATE LED is observed to blink during oven heating, this indicates the particular
RATE 
value entered is too aggressive for the given operating conditions: the oven heater is operating at full power and may not be able to deliver the desired temperature program rate. Such a situation compromises accuracy in repeating the heating ramp from run to run.
Oven safety
Normally, the oven should be switched off ( 
OVEN TEMP 
OFF
) prior to accessing the oven interior (e.g., to change columns, check for leaks, etc.). For safety, this turns off power to the oven heater, fan, and cryogenic valve (if installed), but maintains the setpoint value in memory.
The oven is equipped with a shut•offfeature to protect against unintentional opening of the oven door, and/or the possibility of mechanical and/or electronic failure affecting oven operation.
At any time during normal above•ambientoperation, if the oven cannot attain and/or maintain an entered setpoint temperature, a problem is assumed and the oven is automatically switched off. Examples of possible problems include the oven door open (or closed but not properly latched), inoperative oven vent flaps, failure of the oven fan, heater, or temperature sensor, or electronic problem.
WARNING If the oven door is opened, a time delay may be observed before the oven shuts itself off. The closer the oven is to ambient temperature, the longer the delay will be.
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