Isothermal Airless Oven Heater System; Figure 1-6 Airless Oven - Siemens Maxum II PD PA AP Service Manual

1.3

Isothermal Airless Oven Heater System

The Maxum II airless oven is used to provide a very stable isothermal oven temperature without
the need to supply air to control the oven temperature. This allows for excellent
chromatographic results while reducing utility costs. The interior of the airless oven is
surrounded with heavy aluminum walls that have channels for two cartridge heating elements
and temperature sensors. The walls conduct heat to all sides of the oven. The airless oven
comes configured as two fully independent ovens with separate oven doors. If only one airless
oven compartment is required, then the second compartment is left empty without the
aluminum walls and heating elements.
The approximate internal dimensions of this oven are 226mm (8
and 257mm (10
Figure 1-6
The primary explosion safety system within the Isothermal Airless Oven is the heating and
temperature control system. As mentioned above, the oven is heated using two heating
elements inserted into explosion-proof channels within the aluminum walls. The temperature
of each heating element is detected by a dual-RTD sensor probe that is also inserted into the
aluminum wall adjacent to the heating element. The temperature-limit probe and associated
circuits are not used with the cartridge heaters. The heaters are controlled by temperature
control circuitry on the Power Entry Control Module (or Detector Personality Module) and are
set below the applicable T-rating such that exposed surfaces will not exceed the maximum
allowable temperature. The locations of the temperature probes and heating elements are
shown below.
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001
/ ") deep.
1
8
Airless Oven
1.3 Isothermal Airless Oven Heater System
/ ") wide, 346mm (13
7
8
Oven Types
/ ") high,
5
8
13