Despatch LEB Series - Manual (Page 17)

9
Oven Theory
The oven has an efficient gravity convected airflow to 204°C (400°F). A gravity
convected oven relies on gravity to move air through the chamber. The process of
moving air by relying on gravity is a slow responding process. Thus, the overall
chamber temperature takes a finite amount of time (roughly a few minutes) to soak
in at the desired operating temperature. The time that it takes the unit to soak in at
setpoint is related to such parameters as chamber area, load mass, and exhaust
rate. The unique Despatch design and CONTROL action compensates for this
fact.
The oven uses an indicating microprocessor based digital control that displays the
actual chamber temperature at the sensing point. Despatch strategically locates
the CONTROL's temperature sensor to optimize the control action for the entire
chamber for various load conditions. The CONTROL display will fluctuate a few
degrees around the setpoint, but the overall chamber temperature will remain very
stable. The underlying reason for this is that the display is showing temperature
fluctuations at the temperature sensor location, not the overall chamber
temperature. The strategic location of the sensor compensates for delays in
gravity convection and enhances the performance and temperature control of the
oven. The oven has been engineered to have an overall result of quality
productivity while still maintaining an economical approach and ease of use.