Intake and tank thermometers | Previous Top Next

The thermometer provided within the intake pipe when the ship is built is normally not suitable for the measurement of sea surface temperature. Thus the Member recruiting the ship should, with the permission of the shipping company concerned, install a thermometer appropriate for the purpose. This should preferably be mounted in a special tube providing adequate heat conductivity between the thermometer bulb and the intake water.
When a direct-reading thermometer is installed in cramped conditions the observer should be warned of the possibility of error in his readings due to parallax. A distant-reading system with the display elsewhere (e.g. in the engine room or on the bridge) overcomes this problem. The observer should also be aware that for ships of deep draught, or when a marked temperature gradient exists within the sea surface layer, intake temperature readings usually differ considerably from those close to the sea surface. Finally, of course, the intake temperature should not be taken when the ship is stationary, for then the cooling water is not circulating.