Indicator with anti-tampering circuit for signalling clogging of a filter

摘要

A clogged-filter signalling indicator (10) in a fluidic installation is equipped with an external electrical connector (12) to which leads an electrical circuit contained in the indicator and clogged-condition sensing means (13) which command the circuit to changeover from a first condition to a second condition upon sensing of a clogged condition. In the circuit there is an electrically controllable member (21) for subsequent command of the circuit between the two conditions. This permits verification of the connection of the indicator and the presence or not of tampering. <IMAGE>