Recently Azo Sensors talked to Rotronic Instrument's Director of Environmental Monitoring Systems, James Pickering, about the advantages of using digital sensors in an environmental monitoring system
Environmental parameters are critical to product quality and as of such are controlled and monitored within the pharmaceutical industry.
When certain products are exposed to incorrect temperatures or relative humidity levels the product quality is no longer guaranteed. In the pharmaceutical, cosmeceutical and food industry, this is even more important as consumers' lives can be put at risk due to environmental effects on the products/ingredients such as decomposition, diminished effects/taste, and spoilage.
In the pharmaceutical industry, regulations have been put in place to protect the patients and to deliver quality-assured, safe, and effective products. The temperature range, along with other parameters, to ensure product quality is defined during the product risk assessment.
When a facility is designed, an integral part of the design is the building management system (BMS). The BMS manages many services within a facility including the heating, ventilation, and air conditioning (HVAC) of a building with the help of sensors located throughout the facilities. In order to ensure that the BMS is controlling the HVAC system correctly, an environmental monitoring system (EMS) can be installed. The EMS will monitor all the critical control parameters defined during the product risk assessment at critical locations defined during the facility qualification.
The GxP quality guidelines, developed by the regulatory authorities, are designed to cover the product quality over the complete life cycle of the product.
The GxP guidelines state that the area used must be qualified, the temperature should be monitored, and monitoring devices must be calibrated to meet the guidelines.
The regulations don’t state how to fulfill regulations and as of such, the user can define how they qualify the areas, how they monitor the area, and how often to calibrate the devices.
A digital sensor is a measurement device that sends out a digital signal. The main advantage of a digital sensor compared to an analog sensor is the information sent. Whereas the analog sensor will only send an mA or voltage value (that is converted into a measurement value), a digital sensor can send much more data such as:
The Rotronic digital sensors all have onboard memory and can be user-calibrated/adjusted.
The Rotronic digital sensors communicate to data loggers (wired or wireless) and all communication to the server and database is done digitally as such there is no loss in accuracy during data transmission. This means, unlike analog sensors, no loop check is required during device installation and qualification/validation.
A major advantage of using digital sensors within an EMS is the possibility to use the additional data and reduce the amount of downtime, this is especially valid during the calibration period or during service periods.
With analog sensors, a calibration can be done either in a calibration laboratory (internal or external) or in situ if the application permits. If the calibration is carried out in situ, then then the loop check is also done at the same time. For calibrations carried out in a laboratory, the device needs to be dismounted (leading to system downtime). With the Rotronic digital probes, a simple hot-swap can be carried out resulting in no downtime:
The existing probe can then be calibrated in a laboratory and either put back in its original place or can also be used else where in the facility. Another avantage is that thanks to the digital system and the FDA CFR 21 Part 11/EU Annex 11 requirements, RMS will automatically show that a probe has been replaced with the audit trail together with the time and data and the probe serial number prior to the exchange and the probe serial number after the exchange.
RMS offers a calibration/adjustment feature with the generation of calibration certificates.
Rotronic currently offers the following digital probes:
The Rotronic digital probes communicate via MODBUS via UART.
Rotronic offers a few environmental parameters. However, within the pharmaceutical industry, other parameters also require monitoring. Another parameter that is also measured within cleanrooms is particle monitoring. Rotronic has developed a tool, the RMS-CONVERTER-100 to import third-party devices via their MODBUS TCP communication interface.
Michell Instruments and Rotronic, both part of the Process Sensing Technology (PST) Group, and market leaders in the field of humidity and trace moisture measurements, offer a full range of temperature and humidity calibration equipment and systems.
These include transportable humidity generators for simple verification of relative humidity and temperature probes, pressure swing dryers and low dew-point generators for calibrating trace moisture sensors and instruments. As well as building custom-designed humidity and dew-point calibration systems, we also provide ISO/IEC 17025 accredited relative humidity and temperature calibrations in six locations around the world.
Here is an overview of the applications where temperature monitoring is crucial: