Isothermal Air Bath Oven Heater System (Single And Split); Heater Assembly Purge; Figure 1-1 Pressure Switch And Purge Control Module - Siemens Maxum II PD PA AP Service Manual

Oven Types

1.1 Isothermal Air Bath Oven Heater System (Single and Split)

1.1 Isothermal Air Bath Oven Heater System (Single and Split)
The isothermal airbath oven is the most common oven used in the Maxum II. It is available in
single and split configurations to accommodate a wide range of chromatographic applications.
Because high temperatures are often necessary in order to carry out chromatographic
separations, the isothermal airbath oven heater system is equipped with various safety
features to prevent ignition.
The approximate internal dimensions of this oven are 580mm (22
high, and 267mm (10
1.1.1

Heater Assembly Purge

The airbath oven heater is a purged system. This means that the heater element is located
inside an air purged tubular assembly. Clean instrument air continuously flows over the heating
element and into the oven. This air flow distributes heat to the oven. An air pressure sense
switch mounted on the PCM determines whether air pressure exists in the tubing that supplies
air to the heater. If pressure exists, then air is flowing, and the switch is activated allowing the
oven heater to be energized. If the switch does not detect pressure, then the heater remains
off (power is not supplied to the oven heater). See the photo below. The air supply to the airbath
oven heater system must be free of particulates, clean of any hydrocarbon vapors or other
flammable materials, and dry.
Figure 1-1
8
/ ") deep.
1
2
Pressure Switch and Purge Control Module
/ ") wide, 378mm (14
13
16
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001
/ ")
7
8