Recorders calculate mean kinetic temperature

Edited by the Engineeringtalk editorial team Mar 6, 2006

Once pharmaceutical products have been manufactured, and prior to their despatch, they need to be stored within a carefully controlled storage environment.

Once pharmaceutical products have been manufactured, and prior to their despatch, they need to be stored within a carefully controlled storage environment.

Within the warehouse, temperature and humidity levels must not exceed specified limits, and details of actual variations in these key parameters must be logged in order to meet FDA guidelines.

This may be achieved by monitoring temperature and humidity sensors continuously using a network of highly accurate Eurotherm graphical recorders.

These sophisticated instruments, supported by powerful data display and analysis software, can record and archive data in an encrypted tamper-proof format, allowing the system to support FDA validation and in particular 21 CFR Part 11 compliance.

In a typical installation, which would be required to monitor environmental storage conditions throughout several warehouses, each warehouse would be monitored by a multichannel Eurotherm graphical recorder, such as the Model 6180A.

This instrument, continuously measuring the signals from combined temperature and humidity probes sited at key points within the warehouse, are connected within an Ethernet LAN to a centrally located secure server for long term data storage and supervisory control purposes.

Each data recorder is capable of monitoring up to 48 combined temperature and humidity sensors within each warehouse, and providing a local screen display of both current and recent conditions as well transmitting this information to remote supervisory PCs.

The recorders can flag alert and excursion alarms if warehouse conditions go outside acceptable values, as well as providing alarm summary and alarm history reports when required.

Hard-wired alarm notification can also be provided to local control or security centres.

These recorders are capable of automatically calculating mean kinetic temperature (MKT), and the touch screen interface on each instrument allows individual sensors to be removed from the MKT calculation during calibration.

Preconfigured reports can be generated for each warehouse.

As such systems will be fully validated to FDA 21 CFR part 11 compliance standards, they need to be developed using a formal project lifecycle approach.

Operation will be password protected, with individual user accounts, inactivity timeout, password expiry, and automatic audit trail of operator actions built-in as standard.

Separate, high-integrity data collection will be arranged for each warehouse, usually supported by uninterruptible power supplies for each recorder.

This allows secure local storage of process data, alarm and event data, and audit trail messages.

Automatic archiving of data over the local Ethernet network to a secure server PC is scheduled on a regular basis, allowing site executives to retrieve key data for off-line viewing and report generation.

A typical sensor signal will be brought into each local graphic recorder as a 4-20mA signal.

By calculating a group average of all temperature and humidity readings in the warehouse, alerts and excursion alarms may be set up should readings stray outside acceptable limits.

In order to permit calculation of mean kinetic temperature (MKT) for reports, each channel will have an associated daily maximum and minimum value, which is then grouped and averaged for all sensors in the warehouse.

Individual sensors can be automatically removed from the MKT calculation (for example, when selected for calibration or on a fault condition) by holding the maximum and minimum channels at the last "good" value.

Systems such as these would normally utilise sophisticated software to ensure that each recorder is in constant communication with the central supervisory PC, and that reports are automatically generated and archived on a regular basis.

The Eurotherm Bridge package is designed specifically for this purpose, and has a proven track record with the company's series of graphical recorders The software will allow UHH files of current data and alarms/recent history to be stored locally in Flash memory and then automatically archived at set intervals to the filing system on the central control point (primary server).

This will be done in an encrypted, tamper proof format.

Detailed reports, usually in Excel format, may be generated at any time, and secondary server details can also be set up, allowing each recorder to archive to the secondary server should the primary become unavailable.