发明名称 |
Fail-safe instrument system |
摘要 |
In an instrument system consisting of a transmitter in one location and a receiver in another location connected by a transmission medium, fail-safe operation is obtained by restricting the output of the transmitter to well-defined levels and interpreting any substantial departure of the received signal from these well-defined levels as a failure. When a failure is detected, alarms or other equipment may be activated, including a control circuit which causes replacement of the defective transmitter or transmission medium, thereby restoring the system to service. An embodiment wherein the transmitter is an admittance-responsive transmitter in a two-wire current loop for monitoring the condition of materials is described.
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申请公布号 |
US4363030(A) |
申请公布日期 |
1982.12.07 |
申请号 |
US19790098750 |
申请日期 |
1979.11.30 |
申请人 |
DREXELBROOK ENGINEERING COMPANY |
发明人 |
MALTBY, FREDERICK L.;KRAMER, L. JONATHAN |
分类号 |
G08C25/00;G08B29/04;G08B29/06;G08B29/16;G08C19/02;(IPC1-7):G08B29/00 |
主分类号 |
G08C25/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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