User manual

Table Of Contents
Notes: Item 15 is calculated as Average Down Profile Motor Current less Average Up Profile Motor Current
If ballast is added to pressure housing item 19 is ballast air weight. If ballast is added.
outside the pressure housing item 19 is ballast water weight
Detail of Calculations
The section that follows describes the calculations that are used in the Ballast
Spreadsheet (Excel).
NOTE
The calculation is described here in full so that the process and the potential problems will be
clear. However, the Ballast Spreadsheet (Excel), performs the necessary calculations
automatically after data is entered by the operator.
Measured Weights (note: water weights are to 1g accuracy and air weights are to 10g accuracy)
MMP air weight w/o battery (in g)

Tare water weight (includes test battery air weight)
(in g)

The MMP is buoyant in fresh water (and seawater), so a tare
weight is required to fully submerge it for the water weight
measurement. The water weight of the lead tare weight is
measured using a triple beam balance (+
1g accuracy)
MMP + Tare Water Weight (in g)

Lithium Battery Air Weight (in g)

Check your battery weight (+ 10g)
Calculated Values and Ballasting Constants
1 - MMP Water Weight (in g)

This is calculated as (Item C
Item B) + Item D and is a negative
number because the profiler is positively buoyant.
2 – Ballast Tank Water Temperature (in °C)

In the McLane lab tank, fresh water is used, so the density
depends only on temperature.
3 - Water Density (from table in g/cc)

This is the density, from the table provided with the ballast sheet. If
the ballasting is done in seawater, you would measure the
pressure, temperature, and salinity of the water and calculate the in
situ density using an equation of state.
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