Historically, a small hand-held meter with auto temperature correction had been used. However, recent changes to EP guidelines (4.8) for measuring conductivity clearly required more accurate equipment. Anita Walmsley (Microbiology Team Leader) identified this issue and decided to look at which conductivity equipment was available on the market to satisfy the new EP guidelines.

Three major companies were invited to demonstrate their equipment of which Hach Lange was one (a colleague who purchased Radiometer Analytical Certified pH buffer solutions made the recommendation to Anita).

Anita explains why they wanted to change: “EP requires knowing the cell constant to a very high degree of accuracy (within 2%). Clearly, we
couldn’t do this with our current equipment and therefore decided to
purchase equipment that could guarantee this level of accuracy.”

All three companies demonstrated their equipment. Hach Lange presented the CDM230 with 4-pole conductivity cell (CDC511T) and 0.01D KCl certified standard. Anita decided that the Radiometer Analytical package was the best option. She explains the reasoning behind her decision, “Hach Lange from the outset proposed a complete system that met all criteria laid out by EP.

We were given a full consultation and provided with their application and technical notes detailing the reason for employing a 4-pole conductivity cell with flow body and a 0.01D KCl standard for cell calibration. It was clear that the CDM230 package fulfilled all of our requirements.” These requirements however, could not be met by the competition. “One supplier could not provide a 4-pole conductivity cell, and the other could not provide a flow cell. The flow-cell was a very attractive feature because it not only minimises atmospheric effects but it also ensures minimum volumes of sample and calibration standards can be used. The competitor systems were not as user-friendly as the CDM230. We wanted to programme three methods for our different samples and this was very simple on the CDM230. We can easily switch from method to method. On the other systems this was more complicated and time-consuming.”

The CDM230 was subsequently installed at the Microbiology laboratory with full Equipment Qualification. The complete package was beneficial to Anita, “The fact that Hach Lange could supply everything from the equipment, installation and consumables was important.

We have to be very specific in reporting not only our results but also our commissioning of equipment. The Equipment Qualification package and certification of meter, cell and standards means that our systems are up-to-date and fully compliant for auditing purposes.”

So, how have things progressed since the CDM230 was installed?

“We are extremely happy with the performance of the system. We are very confident in the results we are achieving and happy with the ease of use for our operators. We would recommend this equipment to other pharmaceutical laboratories and we would certainly consider buying Radiometer Analytical equipment in the future.”

To find out more about CDM230 Conductivity Meter, please click here.