For wireless measurement value acquisition on moving parts
Predictive maintenance needs measured data to the greatest possible precision. On components with moving or rotating parts, the relevant measuring points (e. g. temperature of an electric motor’s rotor or planetary gearbox bearing) sometimes cannot be accessed with wired sensors. Accordingly, the data needed for condition monitoring can be obtained only with complex calculations and estimates. However, precise and reliable measured data are obtained only when a sensor is placed directly on the moving part. For requirements of this kind we have developed the telemetry system NORIFID, a simple, cost effective measuring system that is based on established technologies, supplies wirelessly power by induction to a sensor on a moving part, and transmits the measured data via RFID to a fixed receiver.
The NORIFID telemetry system consists of a reader that is fitted on the fixed component and a transponder with measuring element attached to the moving component. This measuring element can be a fixed integral part of the transponder or, if necessary, placed outside at the measuring site and wired to the transponder.
Power and data are transmitted wirelessly by induction, via an RF magnetic field (13.56 MHz RFID). The reader consists basically of a transformer, analysing electronics, and a signal converter and is supplied with voltage from an external source. The transponder likewise is fitted with a transformer, an integrated circuit, and a Pt100 measuring element and is installed on the moving object. It operates passively and therefore does not require its own power supply. The transponder positioned on the rotating object moves cyclically past the reader. When the transponder enters the reader’s range, the reader‘s alternating magnetic field induces a voltage in the transponder’s coil, supplying it with the necessary power. Once the transponder is in the reader‘s active zone, its connected Pt100 measuring element detects the temperature and transmits the measurement value immediately and wirelessly to the reader. Depending on the requirements, the reader then converts and outputs the measuring signals as a voltage or current value.
Customer-specific transponder variants
The transponder can be customised to your application. The standard version consists of the transponder head with male thread and integrated Pt100 measuring element (see Variant 1). If necessary, the transponder can be fitted with a sensor tube containing the integrated Pt100 measuring element (see Variant 2). This sensor tube may be of varying rated length. The Pt100 measuring element may also be fitted externally and connected to the transponder with a cable of varying length (see Variant 3).
Variant 1: Transponder with integrated Pt100
Variant 2: Sensor tube with Pt100
Variant 3: Transponder with external Pt100
|Operating voltage (reader)||9 ... 32 VDC|
|Number of measuring channels||1 ... 5|
|Measuring range||-50 ... 350 °C, application-specific|
|Signal transmission||13.56 MHz RFID|
|Output signal||Current: 0 ... 20 mA, 4 ... 20 mA|
Voltage: 0 ... 10 V, 2 ... 10 V
|Protection class||Reader: IP68, Transponder: IP68|