Medical Device Link.

WEB EXCLUSIVE

Monitoring gas-phase oxygen in centrifuges is a critical tool for the prevention of explosions and fires. An oxygen system developed by Mettler Toledo Process Analytics AG (Urdorf, Switzerland; www.mt.com) provided a customer with an inexpensive, low maintenance and dependable solution. The company in question specialises in the manufacture of active pharmaceutical ingredients, medical devices, nutritional products and laboratory diagnostics. Diabetes care and vascular products are among its areas of expertise.

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The company’s manufacturing process uses multiple centrifuges to separate ingredients from a base liquid for continued processing into finished goods. This is common practice and requires gas-phase oxygen monitoring to be used in the head space of the centrifuge. The O2 measurement is used to control the dosing of inertisation gas (often nitrogen) to neutralise the risk of explosion. Excessive O2 in the process also indicates potential degradation of product quality through oxidation. FM Class 1 Div 1 instrumentation was a requirement in this environment given the explosive nature of the location.

The company had been using an oxygen monitoring system that required time-consuming and costly maintenance. In addition, the sample conditioning requirements were complex and costly.

A Better Solution

It was determined that the company would benefit from Mettler Toledo’s InPro 6800 series sensor with gas phase membrane, coupled with an FM Class 1 Div 1 transmitter 4100 e. This solution provided the level of control the customer required using analogue outputs from the 4100 e. The InPro 6800 features modular construction and an easy-to-replace membrane cartridge. Maintenance is simple and requires no special tools. In fact, the quick-disconnect inner body can be replaced by the company’s own on-site technicians, thus reducing shipping costs and process downtime. Sample conditioning, which was burdensome using the old system, is not necessary with the InPro 6800 sensor.

The device passed the trial period evaluation with flying colours, prompting the customer to order the installation of two additional systems.

Committed to continuous improvement, Mettler Toledo has developed a new M420 transmitter that supersedes the 4100 e. The M420 integrates Intelligent Sensor Management (ISM) technology into a two-wire, loop-powered transmitter designed for hazardous environments. It comes in pH and DO versions, each of which offers mixed-mode inputs for installing analogue or digital sensors with ISM, such as the InPro 6850 i for biotechnology applications. Options also include one or two analogue outputs and the selection of FM Class 1 Div 2 or FM Class 1 Div 1 certification.

ISM technology provides the instant recognition of a sensor’s serial number, part number and calibration information when it is plugged into the transmitter. In addition, the M420 with ISM offers a Dynamic Lifetime Indicator and Adaptive Calibration Timer for both pH and DO. These sensor management functions incorporate dynamic and static measurement values from pH and DO sensor installation conditions. This allows the user to predict the need for pH electrode calibration or replacement and DO sensor membrane or inner body replacement.