| 摘要 |
A monitoring device (1) for monitoring a parameter of water in a water treatment plant comprises a sealed housing (3) of tubular construction, in which the electronic components of the device (1) are housed. A sensor (6) sealably extending from the housing (3) extends through a plug (7) secured in the housing (3). Signals from the sensor (6) are delivered to an analog to digital converter (20) which in turn delivers the signals to a micro-processor (21). The micro-processor (21) delivers the signals in response to a command from a central control apparatus to an infra-red transmitter (22) for transmission to the apparatus. An infra-red receiver (23) receives a signal from the central control apparatus to activate the device (1). A battery (24) powers the device (1). A clear perspex lens (18) sealably closes the other end of the housing (3). <IMAGE> |
