cdm/src/main/java/ucar/nc2/units/SimpleUnit.java
static public boolean isCompatibleWithExceptions(String unitString1, String unitString2) throws UnitException {
    UnitFormat format = UnitFormatManager.instance();
    Unit uu1 = format.parse(unitString1);
    Unit uu2 = format.parse(unitString2);
    return uu1.isCompatible(uu2);
  }
static public boolean isCompatibleWithExceptions(String unitString1, String unitString2) throws UnitException {
    UnitFormat format = UnitFormatManager.instance();
    Unit uu1 = format.parse(unitString1);
    Unit uu2 = format.parse(unitString2);
    return uu1.isCompatible(uu2);
  }
Return true if  unitString1 is convertible to unitString2

@param unitString1 compare this unit
@param unitString2 compare this unit
@return true if the 2 units are compatible
@throws UnitException if units parsing fails