| 摘要 |
The mass addition detector is particularly suitable for use with vehicles. The detector senses change in mass using a combination of one or more load sensors (21) adapted to detect small changes in the mass of a stationary vehicle, discrimination means adapted to discriminate between long term and short term changes and alarm means adapted to provide an indication of any long term mass changes. Preferably, the or each load sensor (21) is attached within the body of the vehicle, for instance by association with the suspension system (23). In one form at least one load sensor (21) is associated with a spring suspension system (23) and senses relative movement between the vehicle body (24) and the spring (23). In an alternative form the load sensor is located on a surface of a resilient mounting bush (22) mechanically joining the spring and the vehicle body. The load sensor may be provided with sensor control means to engage and disengage the sensor from the suspension system. The preferred load sensor is a strain gauge. The discrimination means is a microprocessor programmed to analyse the signals and programmed to analyse the signals so that when a mass change exceeds a predetermined magnitude and lasts for a predetermined time period an alarm signal is produced. |
