1. CMS Galaxy varian CP-4900 GC Gas Analysis
Status of the setup

2. Introduction
The Varian CP-4900 is a gas chromatography system Connected to 46 streams of gas from CMS: CSC, RPC and DT
Setup with three types of detectors:
OV1 (separate hydrocarbons from C4 to C12)
PPU (separate hydrocarbons from C1 to C4)
MS (separate permanent and noble gas)

3. System summarized A gas chromatographic system consists of:
• A regulated and purified carrier gas source, which moves the sample through the GC
• An inlet, which also acts as a vaporizer for liquid samples
• A column, in which the time separation occurs
• A detector, which responds to the components as they occur by changing its electrical output
• Data interpretation of some sort

4. Schematic view Each valves are connected to 16 stream + 1 output.
46 different stream can be analysed:
11 from CSC
6 from DT
27 from RPC

5. SEtup

6. Gc reparation
First problem: Impossibility to modify the position of the valve
- Solved by resetting the position using the manual controller and the multiposition actuator control module
Second problem: Valve automatisation through software not working
- Solved by reconstruction of the system inside the configuration software of the Galaxy GC

7. CHROMATOGRAM

8. Carrier Gas
Use of gas bottles for now because of the possibility of contamination of helium supply lines.
Helium bottle: 40 bar.
Argon bottle: 200 bar.

9. NEXT STEP Check if the helium supply line is contaminated:
Need of high purity heluim to use as carrier gas (Risk of damage of the µGc if not).
Open the gas lines to begin the gas analysis of CMS.