Description Of The Phases Making Up A Program - Zhermack furnace DM Serie Manuel De L'utilisateur

DESCRIPTION OF THE PHASES MAKING UP A PROGRAM

3.6
PHASE 1: programmed start.
The oven can be programmed to come on at a set time even when no members of personnel are in
the laboratory.
The delay interval can be set anywhere between a minimum of 1 minute and a maximum of 7 days.
Use of the delayed start feature is not, of course, necessary for proper oven operation.
PHASE 2, PHASE 3, PHASE 4: temperature increase and holding time.
In each PHASE three (3) data items are entered in the following order:
• Temperature:
Minimum: ambient temperature
Maximum: 1,100°C.
• Increase rate in °C/minute:
Minimum: 1°C per minute
Maximum: the maximum power rating for each model in the DM series (see section 4.1.1).
• Holding (temperature stabilisation) time in hours and minutes:
Minimum: 1 minute
Maximum: 20 hours.
This parameter begins when the oven reaches the set temperature.
PHASE 5
Temperature, increase rate and holding time need to be set for PHASE 5 too. The main difference with
respect to the preceding phases is that the holding time expires and the end of the program is
signalled by an acoustic warning signal (buzzer) lasting 30 seconds.
From that moment on the oven maintains the final temperature setting until the operator switches
the oven off.
After setting PHASE 5 program data it is also possible to set the aspirator switch-off temperature (see
section 7.4).
Not all work phases need be used on all programs; the number of phases employed
depends, in fact, on the desired results. However, its is important that all programs
conclude with PHASE 5.
Special techniques for the melting of specific linings also exist. These techniques allow
oscillating temperature patterns to be used (i.e. lowering the temperature and then raising it again).
For example:
• PHASE 2 - Temperature 250°C - Increase rate 6°C/min - holding time 20 minutes.
• PHASE 3 - Temperature 750°C - Increase rate 10°C/min - holding time 30 minutes.
• PHASE 4 - Temperature 600°C - Increase rate 10°C/min - holding time 30 minutes.
• PHASE 5 - Temperature 850°C - Increase rate 12°C/min - holding time 1 hour.
It is also necessary to set an increase rate of 10°C in PHASE 4 where the
temperature has to drop from 750°C to 600°C: doing so stops the oven
dropping below the 600°C setting.
148 of 272
MAINTENANCE AND USE MANUAL
EN
FURNACE DM