JOWA USA's MetriGuard Water Ingress Alarm System is intended for usage on bulk carriers. It complies with the proposed SOLAS regulations (Chapter XII, Regulation 12) requiring water level alarms in cargo holds and certain other spaces.
The major elements of the MetriGuard Water Ingress Alarm System are:
1. Metritape resistance-tape sensor and sensor housing
2. Float switch and junction box
3. Signal Conditioning Unit with intrinsic safety barriers
4. Alarm unit
Figure 1 shows a block diagram of a typical system. The primary sensor used in the cargo holds and ballast tanks is the Metritape type LA series water sensor. This continuous sensor allows two alarm setpoints to be derived from one sensor. The sensor mounts in a customer stillpipe which protects the sensor from the cargo. A sensor housing bolts to a pipe flange on top end of the stillpipe allowing the sensor to be easily installed (or removed) from the deck. In addition, all electrical connections are made in the sensor housing.