Definition

The DEPTH, in METRES, at which paired protected and unprotected THERMOMETERS attached to a NANSEN BOTTLE are reversed. The difference between the corrected readings of the 2 THERMOMETERS represents the effect of the HYDROSTATIC PRESSURE at the DEPTH of reversal. This DEPTH may then be determined by formula or from a DEPTH ANOMALY GRAPH. DEPTHS obtained by this means are of greatest value when a WIRE ANGLE occurs.