Unmanned Test and Evaluation of the Teledyne Analytical Instruments R-10DN Oxygen Sensor for Use in the MK 16 Mod 1 Underwater Breathing Apparatus

Manned Certification Tests of the Modernized MK 16 MOD 1

“…It is also known that the MK 16 oxygen control sensors are sensitive to temperature. 7 Therefore the temperature sensitivity of the Analytical Instruments PSR-11-33-NM oxygen sensors used in the MK 16 MOD 1 during the present dives was investigated further, and these were found to have poor temperature compensation, with substantial increase in sensor voltage signal with increasing temperature. 8 If sensor voltage signal is increased compared to the time of calibration, this will cause the UBA to control at a proportionally lower PO 2 since the electronics control to sensor voltage set point, not PO 2 per se.…”

“…Nevertheless, NEDU TR 04-28 concluded with the recommendation "The PSR-11-33-NM are recommended for use with MK 16 MOD 0 and MOD 1 UBAs that are calibrated at temperatures close to those of the anticipated water." 7 At that time the actual gas temperatures at the MK 16 MOD 1 oxygen sensors were not known. With this new information it is clear that, for best performance of the MK 16, the oxygen sensor calibration must take place at a temperature substantially above expected water temperature.…”

“…This temperature is about 25 °C (45 °F) higher than the calibration temperature. The report from previous testing of the Analytical Industries PSR-11-33-NM indicate that the oxygen sensor voltage output could have increased by about 14% when the temperature increased by 25 °C (0.55% per °C) 7. This would result in a reduction of 14% from a PO 2 set point of 1.3 atm to 1.11 atm, even though the secondary display would read 1.30.…”