Resistivity and Conductivity Measurements using Memosens Digital Sensing Technology
Ultra Pure Water (UPW) systems use resistivity or conductivity measurements to identify ionic contamination. The same equipment measures resistivity and conductivity since they are reciprocals of one another. They have two different measurement units. We typically use resistivity units (MΩ•cm) in semiconductor manufacturing and conductivity units (μS/cm) in the power and pharmaceutical industries.
Ultra Pure Water is critical for silicon wafer and pharmaceutical production as well as power generation. The target resistivity of UPW in semiconductor fabrication (FABs) is 18.18 MΩ•cm at 25 °C. This allows the UPW to clean the silicon wafers properly during manufacturing. In the case of pharmaceutical manufacturing the conductivity of UPW must be <1.3 μS/cm at 25 °C to ensure the purity of the final product. Steam generation requires UPW to be <10 μS/cm in order to prevent damage to the boiler.
Solution for UPW Resistivity and Conductivity
The SE 605 Memosens sensor can measure resistivity up to 25 MΩ•cm or conductivity to as low as .04 μS/cm. The Stratos Multi transmitter gives you the ability to select either resistivity or conductivity for the measurement display and output. Coupling the SE 605 with the Stratos Multi transmitter is a cost-effective solution because it provides the ability to operate two separate measurements from the same transmitter. You can pair two conductivity/resistivity measurements together or you can make the second channel pH or dissolved oxygen.
Memosens technology allows you to perform all calibrations and maintenance offline in the analyzer shop or laboratory. When performing field service on a sensor, just take a pre-calibrated sensor to the field and do a hot-swap by disconnecting the Memosens cable and connecting the new sensor. The sensor share calibration information automatically with the system and is ready to measure without any additional steps. Technicians can now take the sensor back to the shop and service it in a controlled environment at a time that best suits them.
Furthermore, Knick Memosens sensor connections are inductive, plastic, and immune to moisture and corrosion. You can even connect a sensor while it is completely submerged.
What was this Customer’s Return on Investment?
- Product and process quality assurance: Reliable resistivity and conductivity measurements ensure product quality specifications are met and prevents damage to critical process equipment.
- Reduced maintenance time and costs: By using Knick Memosens sensors and transmitters, the customer greatly reduced the calibration frequency. This means fewer trips to the field to re-calibrate sensors leading to reduced maintenance costs.
- Reduced sensor & transmitter replacement costs: The SE 605 sensor’s inductive connection and the Stratos Multi’s sealed transmitter design allows the system to operate in humid/wet locations without worrying about the corrosion of metal components and damage to exposed circuit boards. The Stratos Multi transmitter comes with a three year warranty.
