How to Disassemble the Extraction Lens-Omega X-Lens Assembly for Agilent ICP-MS Systems

Answer

This Information Applies To: Agilent ICP-MS systems (7800/7850/7900/8800/8900)

Issue

The lenses should be cleaned if any of the following symptoms are observed:  

• The signal is unstable - For example, more than 10% signal drift in an hour. This may also be caused by other parts such as sample introduction.  
• The lens voltage is changed in the MassHunter software, and the resulting signal changes very slowly - For example, if you change the parameters drastically step by step, it will take more than 1 second for the signal to stabilize.  
• When changing the parameters during tuning, the response speed of the signal is different when changing the value from the plus direction and changing it from the minus direction.  
• Contamination symptoms or concerns are present.

Requirements

This procedure assumes that the ICP-MS is in Standby mode and the Sample and Skimmer Cones have been removed. 

Items Required

You will need the following equipment for disassembling the X-Lens.

• Safety glasses 
• Laboratory gloves 
• Allen wrench (included in the tool kit) 
• TORX driver (T8, T10)

Steps to Follow

1. Loosen the three screws from the skimmer base using an Allen wrench (3 mm.) 
2. Carefully remove the extraction lens-omega lens assembly from the instrument. Place the extraction lens-omega lens assembly on a clean surface. 
3. Use the skimmer wrench to disassemble the Extraction lens-omega lens assembly. Start disassembly by removing the two Lens Screws (see 7 on Figure 1) using a TORX driver.
4. Once the Lens Screws are removed, the various lenses and spacers in the stack can be disassembled (see Figure 1).
5. After disassembly, the lenses can then be cleaned following the instructions provided in the user manual.

Caution: The spacers can stick to gloved hands due to static and are easily displaced from the work area.  Take special care to contain the spacers so they are not lost. Dismantle the lens in an area free of contamination.

Tips: The Extraction Lens-Omega Lens assembly is located through the interface behind the Skimmer Cone. The Sampling and Skimmer Cones must be removed before removing the Extraction Lens-Omega Lens assembly.  When removing the Extraction Lens-Omega Lens assembly, it is not necessary to open the vacuum chamber

Figure 1. X-Lens Assembly Breakdown
1. Skimmer Base 2,  Extraction Lens 1, 3. Extraction Lens 2, 4. Omega Lens-x,  5. Spacer, 6. Omega Bias-x, 7. Lens Screws

Table 1. Ion Extraction X-Lens Assembly Part Numbers.