Alarm Monitoring & Control System (AMCS) · Automation & Control
Crew members, engineers, and operators on board vessels depend on reliable temperature sensors to monitor critical systems. Kongsberg Maritime offers the MN681 low-temperature resistance sensor with cable, essential for measuring temperatures in harsh environments such as stern tube bearings. Designed to withstand extreme conditions, this sensor has a wide operational range of -50°C to 100°C and is equipped with a robust IP67 protection rating. Its double T2150 or Pt100 sensor element ensures accurate readings, while the 2x2 or 3-wire connection supports flexible installation options. Constructed from brass and weighing approximately 535 grams (MN2682TU60), this sensor is a trusted tool for maintaining safe and efficient operations in demanding maritime settings.
| Alarm point functional/loop test | annual, per class requirement for the alarm monitoring system |
|---|---|
| Sensor calibration check | annual or per manufacturer recommendation |
| AMS software/backup verification | annual, tied to class survey |
| Cable/connector inspection | annual or at drydock |
| Temperature reading accuracy/drift | should remain within the manufacturer's stated accuracy band - confirm against the calibration certificate and recalibrate or replace if drift exceeds it |
|---|---|
| Alarm response time | should remain within the system's configured delay/response time - a markedly slower response than the commissioning baseline can indicate sensor or wiring degradation |
| Sensor cable insulation resistance | should remain within an acceptable range for a low-voltage instrumentation circuit - a marked drop from baseline suggests moisture ingress at the gland or connector |
Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.
The alarm and monitoring system is subject to annual functional testing under class rules, typically as part of periodic survey of the automation/unattended machinery space notation. Class wants records of alarm testing, especially for points tied to the engineer's/dead-man alarm functions in an unattended machinery space (UMS).
Estimated lifetime: Not conventionally rated in running hours. Temperature sensor elements and associated cabling in an alarm monitoring system typically remain in service 10-15 years before wholesale renewal, though individual sensor failures occur earlier and are handled as routine spares replacement.
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