INFORMATION FOR BODC SERIES REF. NO.    41158                  
                                                                                
 ===============================================================================
                                                                                
                         Sea Floor Pressure Gauge Inventory Number :   7025     
                                                                                
 Start Time : 11 Sep 1975 0752 GMT                  Latitude  :  53deg 30.6min N
 End Time   : 06 Oct 1975 1838 GMT                  Longitude : 025deg 05.6min W
                                                                                
 Nominal Cycle Interval   :  900.0 secs         Sensor Depth    :   3508.00m    
                                                Sea Floor Depth :   3508.00m    
                                                                                
 Positional Uncertainty   : 0.1 to 0.5 n.miles                                  
 Depth Datum              : Instantaneous                                       
                                                                                
 Data Category            : Offshore sea floor pressure series                  
 Instrument Type          : Tide gauge (unspecified)                            
 Instrument Mounting      : Sea floor - fixed                                   
 Originator Laboratory    : Proudman Oceanographic Laboratory, Bidston, UK      
 Originator's Identifier  : D6MP10/PDFH4                                        
                                                                                
 ===============================================================================
                                                                                
 Additional information stored with the data:                                   
                                                                                
    Clock lost 26 seconds over 25 days 10 hours  45  minutes  26  seconds;  the 
    cycle interval and time values have been corrected.                         
    Instrument Characteristics                                                  
    Station D6                                                                  
    OSTG Mark III, number 16 Sensors HP Quartz (BODC Series Ref. 41158)         
                                     SG 1/D4   no data returned                 
                                                                                
    Nominal sampling interval       900 seconds                                 
    Integration period              890 seconds                                 
                                                                                
                              --------------------                              
                                                                                
                                                                                
    I.O.S. Data Processing of Off-Shore Pressure Recorder Data 3                
    Data processing comprises 2 stages:-                                        
    1. Instrumental drift and depth are removed, thus the drift free series  is 
       produced with an artificial mean of zero.                                
    2. Generally the pressure values have  been  obtained  by  integration  and 
       averaging  over  the  sampling  interval, followed by logging; hence the 
       time value assigned to a data cycle has been  chosen  as  the  mid-point 
       between  the  start and end time of each interval. Some pressure records 
       have been sample rate reduced from the basic time step of  the  recorder 
       to  produce  either hourly or 15 minute values, incorporating any timing 
       corrections due to clock error.                                          
                                                                                
 -------------------------------------------------------------------------------
                                                                                
 The following additional documents apply to this series:                       
                                                                                
  34098; I.O.S. Off-Shore Pressure Recorder Mark III
                                                                                
 ===============================================================================