Siemens Maxum II Service Manual

Detector Overview
1
Several different types of detector modules are available for the Maxum ll as follows:
● Thermal Conductivity Detector (TCD) - This is a concentration responsive detector for
moderate sensitivity of most components. It is available as an 8 cell version with thermistors
or as a 2 cell version with filaments.
● Flame Ionization Detector (FID) – The FID is a very sensitive detector for combustible
hydrocarbons.
● Flame Photometric Detector (FPD) – This is a selective detector used to detect substances
containing sulfur.
● Pulsed Discharge Detector (PDD) – This detector is manufactured by Valco Instruments
Inc. It can be equipped to operate in either the Helium Ionization, Photo Ionization, or
Electron Capture modes.
All of the detector modules within the Maxum II can be used in conjunction with both air bath
and airless ovens. Depending upon the application requirements, a Maxum II can include up
to three detector modules in a single air bath oven, or up to 2 detector modules, one for each
oven, in an airless oven. Three detectors are used in special configurations.
With the exception of the thermal conductivity detectors, the detector modules are mounted
in the detector compartment. The detector compartment is located between the electronics
enclosure (EC) and the oven. The detector compartment houses the detector modules and
provides a safe path for the electrical connections between the detector modules and the
detector personality module (DPM). It also allows the detector to easily connect to the analytical
components in the oven.
The detector specifications given in this section depend on the specific application in which
they are installed, and reflect the performance of the component when used in a Maxum II Gas
Chromatograph as a system.
1.1 DPM Types
Three DPM types are used for temperature control and detector interface:
● Intrinsically Safe Thermal Conductivity DPM
● Base3DPM
● Temperature Control Module (TCM)
The interfaces available for each are shown in the table below.
Function TCM IS-TCD DPM Base3DPM
Temperature control x x
Intrinsic safety x
Detector inferfaces:
RTD x x
Maxum Edition II Detectors
Service Manual, May 2018, A5E42019847001 5

Siemens Maxum II Specifications

General

Category	Gas Chromatograph
Measurement Principle	Gas Chromatography
Communication Protocols	Modbus, Ethernet, Profibus
Operating Temperature	-20°C to 55°C
Power Supply	24 VDC or 100-240 VAC
Mounting	rack mount
Applications	Refinery, chemical, petrochemical, natural gas
Detectors	Thermal Conductivity Detector (TCD), Flame Ionization Detector (FID)
Sample Inlets	Multiple
Dimensions	Varies by configuration (e.g., 19" rack mount)