old_contents: """
      sonde.quantities
      ~~~~~~~~~~~~~~~~
  
      This module contains a few custom quantities that are used
      primarily for unit conversion.
  """
  from __future__ import absolute_import
  import quantities as pq
  
  
  #: Unit of concentration - milligrams per liter
  mgl = pq.UnitQuantity('Concentration',
                        pq.CompoundUnit("mg/L"),
                        symbol='mg/L')
  
  #: Unit of specific conductivity - milliSiemens per centimeter
  mScm = pq.UnitQuantity('Specific Conductivity in MilliSiemens per Centimeter',
                         pq.CompoundUnit("1e-3*S/cm"),
                         symbol='mS/cm')
  
  #: Unit of turbidity - nephelometric turbidity units
  ntu = pq.UnitQuantity('Turbidity',
                        pq.dimensionless,
                        symbol='NTU')
  
  #: Unit of salinity - practical salinity units
  psu = pq.UnitQuantity('Salinity',
                        pq.dimensionless,
                        symbol='PSU')
  
  #: Unit of specific conductivity - microSiemens per centimeter
  uScm = pq.UnitQuantity('Specific Conductivity',
                         pq.CompoundUnit("1e-6*S/cm"),
                         symbol='uS/cm')
  
  #: Units of Depth/Water Surface Elevation - meters/ft of water
  #mH20 = pq.m * pq.conventional_water
  #ftH20 = pq.ft * pq.conventional_water
  mH20 = pq.UnitQuantity('meters of water', pq.m * pq.conventional_water, symbol='mH20')
  ftH20 = pq.UnitQuantity('feet of water', pq.m * pq.conventional_water, symbol='ftH20')
  
  #: Pressure in dbar
  dbar = pq.UnitQuantity('decibar', pq.CompoundUnit('0.1*bar'), symbol='dbar')
  
new_contents: """
      sonde.quantities
      ~~~~~~~~~~~~~~~~
  
      This module contains a few custom quantities that are used
      primarily for unit conversion.
  """
  from __future__ import absolute_import
  import quantities as pq
  
  
  #: Unit of concentration - milligrams per liter
  mgl = pq.UnitQuantity('Concentration',
                        pq.CompoundUnit("mg/L"),
                        symbol='mg/L')
  
  #: Unit of specific conductivity - milliSiemens per centimeter
  mScm = pq.UnitQuantity('Specific Conductivity in MilliSiemens per Centimeter',
                         pq.CompoundUnit("1e-3*S/cm"),
                         symbol='mS/cm')
  
  #: Unit of turbidity - nephelometric turbidity units
  ntu = pq.UnitQuantity('Turbidity',
                        pq.dimensionless,
                        symbol='NTU')
  
  #: Unit of salinity - practical salinity units
  psu = pq.UnitQuantity('Salinity',
                        pq.dimensionless,
                        symbol='PSU')
  ppt = psu
  
  
  #: Unit of specific conductivity - microSiemens per centimeter
  uScm = pq.UnitQuantity('Specific Conductivity',
                         pq.CompoundUnit("1e-6*S/cm"),
                         symbol='uS/cm')
  
  #: Units of Depth/Water Surface Elevation - meters/ft of water
  #mH20 = pq.m * pq.conventional_water
  #ftH20 = pq.ft * pq.conventional_water
  mH20 = pq.UnitQuantity('meters of water', pq.m * pq.conventional_water, symbol='mH20')
  ftH20 = pq.UnitQuantity('feet of water', pq.m * pq.conventional_water, symbol='ftH20')
  
  #: Pressure in dbar
  dbar = pq.UnitQuantity('decibar', pq.CompoundUnit('0.1*bar'), symbol='dbar')
  
subject: add a ppt to sonde.quantities - for now it is the same as ppt