The new InduCon system from Knick is an inductive and hence contactless plug connection between sensor and cable, enabling reliable pH measurement unaffected by ambient conditions. System partners are Mettler Toledo, Hamilton and Scott Instruments.
Many interference problems with contact-based connector systems caused by humidity, dirt or corrosion are completely eliminated. The system reliably prevents any coupling between medium and transducer potentials.
The use of InduCon ensures that there are neither EMC problems nor superimposed potentials and distorted measurements. Instead of a high-resistance special pH measuring cable, a digital data transmission cable is all that is needed to connect InduCon. Large distances of up to 150m between the sensor and the process analyser present no problems because of the digital signal transmission.
The InduCon connector system has the benefit of the simplest possible mechanical operation to prevent any confusion, with haptic/kinesthetic feedback or, to put it more simply, ‘plug and click’. It can be inserted and locked in any position with no twisting of cables. An external hygienic seal prevents bacteria from penetrating into the gaps between the sensor cap and the cable socket. The whole system can even be cleaned with a high-pressure cleaner (IP69K protection).
InduCon is intrinsically safe and can be operated with 2-wire loop-powered transmitters. Despite the associated minimal power consumption, it has been possible for the first time to provide an additional optical status display on the connector. The integration of a red and a green LED directly within the cable socket signals the state of the system locally.
Synchronous measurement of pH and ORP values with a single sensor is now possible, as well as the quantitative measurement of glass and reference impedance, indispensable for reliable sensor diagnostics. Intrinsic safety certified by the German PTB.
Hardware and software are in accordance with IEC61508. With the right configuration, the system can be deployed according to SIL2(SWSIL 3) requirements, regardless of the type of pH sensor selected.
InduCon turns pH electrodes into digital sensors with integrated data storage. A variety of sensor data – eg, sensor type, operating hours, calibration history – provide for predictive maintenance and increase the availability of the measuring point. Sensors swapped over in error are detected and rejected. Four calibration/adjustment records are stored and can be documented. Storing sensor-specific utilisation data allows the projected service life of the sensors to be recorded.
InduCon enables a quick and easy exchange of pre-calibrated sensors – costly calibration in the field is replaced by convenient and rapid calibration in the laboratory. The portable analyser PortamessS can be used as a static or mobile calibration station.
Laboratory calibration reduces the time spent by highly qualified staff in hazardous, inaccessible or inhospitable areas to the minimum. Maintenance costs decrease and the availability of the measuring point increases.
Features include: Contactless, inductive connector system eliminates all measuring problems caused by humidity, corrosion, salt bridges, problem contacts, poor galvanic isolation and too long or unsuitable cables; maximum availability of the measuring point through the use of precalibrated sensors; simple, reliable plugging and locking with no twisting of cables; hygienic design prevents bacterial deposits in gaps or exposed cavities; high-pressure cleaning and autoclaving (IP69K protection); CheckLight: red and green LEDs signal transmission status and sensor diagnostics; SensoCheck: monitoring of glass and reference electrodes during pH measurement; synchronous measurement of pH and redox with one sensor; quantitative determination of glass and reference impedance; sensor and calibration history with significantly enhanced predictive sensor diagnostics; SIL2(SW SIL 3) according to IEC 61508; intrinsically safe according to ATEX and FM; compatible with 2-wire transmitters.
Carsten Koska is with Knick Elektronische Messgeräte GmbH & Co KG, Berlin, Germany. www.knick.de
