Pressure Transmitter Closing the Validation Gap in the Pharmaceutical Industry
Damaged or cracked metal diaphragms are one of the most frequent causes of failure in pressure transmitters. The result is that isolating diaphragm liquid (50–2500 µL), which serves as a transmission medium between separating diaphragm and sensor element, leaks into the process. The isolating diaphragm liquids used are generally subject to FDA regulations and are not harmful to health. For the plant operator, however, they represent a product quality risk. The implemented transmission oils don’t mix well with the water-based pharmaceutical products — serious contamination is sometimes the result. The pressure transmitters with ceramic-capacitive Certec measuring cell from Vega offer a solution for these quality and validation processes. The measuring cell works without transmission liquid and ideally satisfies all requirements of the pharmaceutical industry. It is dry, self-monitoring and registers both damage to the diaphragm and moisture leaking into the sensor. The diaphragm, which consists of sapphire ceramic, is 10 times harder than high-grade steel and easily defies abrasive media. The ceramic diaphragm and ceramic body are joined together with glass solder, allowing a constant product temperature up to 150 °C. The high surface quality guarantees optimal cleanability and sanitation. Furthermore, depending on process requirements, a double seal or a hygienic form seal can be implemented.