| Imagine a sensor, such as a load cell or extensometer fitted to a materials testing machine, which communicates digital information about itself to the machine controller and testing software as soon as it is plugged in.
Zwick's smart sensor technology has come a long way since it was introduced way back in the early 1990's. Sensors have the manufacturer, type, serial number, calibration date, and other important data digitally embedded in the connecting plug.
How does this technology work?
As soon as an operator plugs a load cell or extensometer into the test machine, the controller reads all data from a chip in the connection plug, recognises the sensor and how to use it. The chip contains digitally stored information such as:
Sensor serial number
- This can be automatically stored with results and printed on test reports, and provides a reliable and traceable connection between the raw data and the measuring device.
Sensor Calibration details
Nominal Value
This tells the test machine electronics the capacity of the sensor, for example 10kN load cell or 60mm extensometer.
Resolution
Informs the electronics about the smallest value the sensor is able to measure.
Overload limits
Informs the electronics about the safety limits for each sensor to avoid mechanical damage due to overloads - whether in tensile or compression mode.
Calibration Date
When systems are calibrated to International Standards by Zwick's calibration laboratories, the next calibration date is stored on the sensor chip. The testing system then automatically reminds the operator when the next calibration is due. This helps to make sure that the testing machine is always working within its calibration dates.
Calibration data
Allows analogue sensors to have their characteristics matched precisely to external calibration equipment. Zwick sensors generally have excellent linearity, but this function enables an even better correlation. For digital sensors, such as the high resolution extensometers normally used by Zwick, this function merely sets the maximum scale value.
In addition, Zwick also uses the smart sensor technology for sub components of a sensor. One example is Zwick's multiXtens digital extensometer which can be configured for room temperature tensile testing, elevated temperature testing, or flexural testing. All of these individual components also have built in smart chips which inform the controller about the options connected. This helps the operator to make the change from one test type to another quickly and easily, and without the need to make adjustments or change settings.
Zwick's existing customers have taken such technology for granted over the past 17 years and they rely on these systems to ensure that the test results they get are traceable and free of manual errors.
With the introduction of the new TEDS (Transducer Electronic Datasheet) via IEEE1451 more and more sensor manufacturers are building devices with built-in chips. Zwick's smart sensor technology already uses much more information than will be required by the IEEE1451 Standard but, in future, all products from Zwick will also include a TEDS interface protocol. |
