Agilent Markes UNITY Thermal Desorber Teardown – Gas Chromatography

Teardown of the Agilent Markes UNITY Thermal Desorber. Which contains a cold trap (Peltier) and some very fine fluid mechanical parts. A thermal desorber is used as a part in the chain of machines used in Gas Chromatography. I have previously done a teardown of a temperature column for HPLC. The Thermo Scientific Dionex TCC-3000SD Standard Thermostatted Column.

Agilent Markes UNITY Thermal Desorber Pictures

The unit was in fairly good shape when I got hold of it. It was missing a few enclosure parts and lids and was scratched up.

The gas input and output ports are all located in the front behind a lid. A lot of small micro tubes, tee’s, valves, solenoids and connectors come to sight. Processing air and exhaust gas ports are on the backside. The Precision Dynamics, Inc. solenoids appear to be of very high quality.

A peltier driven cold trap is used for cryogenically narrowing down the chromatographic band and improving the detection limit.

The main circuit board uses a Infineon SAB-C167CR-LM controller IC. The IC is marked with Siemens and date code 1995. It is most likely running at 5 MHz, judging by the nearby 5 MHz crystal.

It is a 16-bit CPU with 4-Stage Pipeline with a large variety of built-in features: On-Chip Memory Modules. 2 Kbytes On-Chip Internal RAM (IRAM). 2 Kbytes On-Chip Extension RAM (XRAM). 128/32 Kbytes On-Chip Mask ROM. On-Chip Peripheral Modules. 16-Channel 10-bit A/D Converter. Two 16-Channel Capture/Compare Units. 4-Channel PWM Unit. Two Multi-Functional General Purpose Timer Units with 5 Timers. Two Serial Channels. On-Chip CAN Interface. Up to 16 Mbytes External Address Space for Code and Data.

The power supply unit is a Lambda Alpha 400W, model CA400 5A 12/12E, with a date code from 5th January 2005. It is a modular power supply with 5 slots for different output voltages. Firstly slot 1 and 2 are populated with a 5VDC 60A module. Secondly slot 3 is populated with a dual 12V 8A module. At last slot 4 and 5 are not used.