The correct operation of assets in many industries are dependant on the clamp force exerted by bolted fasteners present on the asset. One example is the fasteners on the safety critical stretcher bar found on railway switches, another being the bolts that provide the compressive force needed to expand the stem seals in valves, via the gland plate and followers, and another being the bolts associated with flanges.
Smart Component Technologies have developed a Smart Washer technology designed specifically to measure the clamp force of the bolted fasteners as found on the safety critical stretcher bar and are actively seeking to migrate the technology to other markets.
In use the Smart Washer and associated infrastructure is designed to operate in two distinct modes: condition monitoring and performance monitoring.
The Smart Washer is a device that enables the clamp force associated with a bolted joint, fixing or fastening to be measured; the data being transmitted to a collection point for processing, storage or onward transmission. This is achieved by means of novel clamp force sensors, near-field and far-field communications devices and low power embedded electronics; all packaged in the form factor of a modified washer.
Smart Washer features
- Embedded (sealed) clamp force measurement system.
- Supplementary sensors, e.g. acceleration, inclination can be added.
- Unique ID, clock-timer, memory battery condition and battery charge functions.
- Configurable multi-channel wireless transmission of data to Smart Access Points.
- Data transmissions triggered by clock or sensor condition.
- Reconfigurable by means of a secured near-field channel by Smart Reader.
- Battery rechargeable over the near-field channel; no need to remove washer.
- All Smart Washer to Smart Reader interactions are monitored via the Smart Access Point; anti-tamper and compliance.
Smart Access Point
In a condition monitoring mode, clamp force samples are taken periodically in units ranging from minutes to days, and relayed to the user. The system is able to monitor itself and thus provide asynchronous event notification in response to “events”, such as change a percentage in clamp force.
To deliver this mode of operation the Smart Washer transmits the sampled clamp force measurement as a packet of information to a Smart Access Point that in turn relays the data to the user via standard network and cloud services.
Smart Access Point features
- Collects wireless transmissions from the deployed Smart Washers.
- Processes, stores or relays data to internet/cloud services, databases etc.
- Embedded 32 bit microprocessor, supporting standard interfaces.
- Embedded USB, Ethernet, Wi-Fi and GSM/3G connectivity.
- Unique ID, clock-timer, memory.
- Power supply 5V/1A.
In a performance monitoring mode of operation, samples are taken more frequently (e.g. 10 samples per second) with the sampling being initiated manually and on a washer-by-washer basis. The purpose of this mode allows the user to see the applied clamp force change in near-real-time i.e. when tightening or loosening the fastener.
The Smart Reader is responsible for receiving, storing and forwarding the data being collected from the washer when used in the performance monitoring mode of operation. In addition, The Smart Reader is the device that allows the washer to be configured appropriately.
Smart Reader features
- Provides near-field communications with the Smart Washer.
- Allows a Smart Washer to be reconfigured by means of secured near-field channel.
- Allows a Smart Washer battery to be recharged and near field interactions to monitored.
- Receives Smart Washer far-field data and acknowledgements over reserved channel.
- Rugged, hand held device which can be left on track once clipped to washer.
- Smart Reader accessed from a safe distance from tablet, phone or laptop via Bluetooth 4.0 or a USB tether.
- Rechargeable battery 7.5V/5.4A.