There were two 20-30 phone interviews that mainly addressed my background, interest in the job/company, general experience and knowledge of chromatography, electronics, software, my experience/qualifications, and my salary expectations.
The in-person interview was about 2 hours total and I met with two supervisors and a regional manager. We talked about my experience, items on my resume, reasons for the job hunt, my work ethic. They wanted to see that I had knowledge of the company and that I was aware of the travel required for the job. They asked me a number of questions about the theories behind HPLC, IC, GC, ICP, UV-Vis, TOC, and specific troubleshooting questions relating to each technique.
According to everyone I have spoken to, SSI aims to promote employees from within and have people stay with the company for many years. Therefore, this is a company that wants to hire hard-working, ambitious, and loyal people who also really know their stuff.
If you interview for a job like this, study up on theory behind their products. Know what they offer. Know about the company and why you want to work there. Be knowledgeable enough on how these instruments work to answer troubleshooting questions, see below for examples (e.g. If your peak retention times shifted forward on an HPLC run, how would you approach fixing it? If you noticed a drop in detection limits on an ICP-OES run, what would you look at? If you weren't getting a signal on a TOC analyzer, what would you check?)