In late 2013 and the early part of 2014 we experienced an unprecedented level of APD14 cell issues and resolving these was our main priority. In July 2014 a number of major changes were made to the water repelling cell face, the cathode and the cathode housing were modified to ensure the cathode remained lubricated in all conditions which both extended the life of the cell and increased stability.
After 8 months of use, we are very pleased to report that on cells with date code July 2014 onwards, the targets of stability and longevity have been achieved.
We can now report that the APD14 has an excellent performance record and has the lowest return rate of any oxygen cell we have sold in the past 18 years.
Due to efficiencies in the supply chain we are able to offer the APD14 slightly cheaper than the APD16.
The additional advantage of the APD14 over the APD16 cell is that it does not require the diver to make adjustments to the Gradient Factor (see below).
Please Note if using APD16 or Narked@90 Cells:
While the APD16 & Narked@90 cells are very stable they have an unfortunate trait in that once the Inspiration scrubber warms up from top to bottom, which is 15 to 20 mins after the start of the dive, the cells read 0.05 bar higher than the actual PO2. Therefore, you need to adjust the Gradient Factor down.
It is quite in order to use a mixture of the two types of cell, APD14 and APD16, but please bear in mind the dominant two will determine whether you need to adjust the GF high or not. i.e. if you have two APD14s and one APD16 then you wouldn’t need to make the GF high adjustment.