Visual control system improves autoclaves

Edited by the Engineeringtalk editorial team Nov 15, 2002

Salisbury based autoclave engineering company AMC has developed a simple and cost-effective way of upgrading the control systems used on these important items of sterilisation equipment.

Salisbury based autoclave engineering company AMC has developed a simple and cost-effective way of upgrading the control systems used on these important items of sterilisation equipment.

By controlling the timed autoclave heating and pressure cycles via a standard Eurotherm Visual Supervisor controller, which includes a large touch-screen interactive display, the company can offer operational flexibility, high reliability and an exceptionally clear user interface.

Controlling microbial contamination through sterilisation has long been considered the most essential component of infection control programmes.

Autoclaves (steam sterilisers) are the most widely used method of sterilisation for instruments and materials used in the medical and scientific worlds.

Temperature, pressure (including vacuum), and time are the main factors of the steam sterilisation process.

Generally, the higher the temperature selected, the greater the pressure and the shorter the sterilisation cycle.

Maximum temperatures are about 136C while pressures can be as high as 3200mbar, vacuums to 50mbar.

Autoclaves produced or refurbished by AMC now exclusively use a control and monitoring system based on Eurotherm's well established Visual Supervisor, a powerful multifunction control and display product, which in effect is a process controller, data logger, setpoint programmer and interactive touch screen display in one unit.

It is compact, simple to use and is capable of performing both continuous and sequential control functions.

The system features comprehensive alarm and event management, powerful trending, setpoint programming as well as local data logging facilities.

Because of its open network architecture, the system may also be connected to a wide range of third party process interface I/O modules - including Eurotherm's proprietary 2500 System multiple loop PID controller.

In this demanding application the pressure, temperature and timing of the sterilisation process is closely monitored and controlled by Visual Supervisor via a 2500 System, allowing different preset temperature/pressure profiles and program sequences to be controlled accurately without operator intervention.

Data and system status can be viewed in real time on the Visual Supervisor touch screen, logged continuously to 3.5in disc, and fully detailed historical records printed out via a separate printer.

Using Eurotherm's proprietary Project Studio software, AMC has developed a number of unique user screens, providing the operator with a clear and comprehensive view of the sterilisation process.

In this instance, the 2500 System is configured using an eight I/O module base, through which temperature and vacuum/pressure control loops are connected.

Outputs include control signals for steam valves, pressure or vacuum pumps and alarms.

Gary Singleton, AMC's Managing Director, believes that the Visual Supervisor based control system brings significant advantages to end users, to support engineering staff, and to OEMs like his own company.

He comments: "When Visual Supervisor first became available, we saw immediate potential advantages for the type of self-contained, high performance OEM application like ours.

Configuring it for use in an autoclave environment was not difficult, and Eurotherm were able to provide high standards of technical support.

Customers are very satisfied because they have reliable, clear and unambiguous control routines which can be programmed and amended on screen, while service and validation personnel can access historical and diagnostic data easily.

We like it because in engineering terms it is the most accurate and reliable solution we have yet found, and the long-established Eurotherm name is both familiar and acceptable to virtually every customer".