AP CO2 Sensor

The AP CO₂ Sensor
The AP Diving CO₂ Sensor (RB120) is an ‘active warning device’ designed to alert the diver when the CO₂ content of the breathing loop is approaching a dangerous level. This could be due to depletion of the CO₂ absorbent canister or incorrect assembly resulting in CO₂ bypass of the canister.

The CO₂ Sensor has been specially developed for use with AP Diving’s range of rebreathers equipped with Vision electronics.

The sensor is intended as an option that can be used with or without the APD Scrubber monitor (Temp-stik).

Simple Plug & Play operation: Providing the Vision electronics are programmed with the latest release* of embedded software you simply plug the CO₂ sensor into the lid connection. The firmware recognises the CO₂ sensor and activates the appropriate displays and warnings.

         *The latest release version is V05.01.02, released on July 19^th, 2013

• Monitors CO₂ levels within the breathing loop and warns the diver prior to the level becoming harmful
• Single warning level when the diver should ascend immediately and bailout from the rebreather loop
• Warnings are displayed on the Vision handset and via the HUD and the audible alarm
• Sensor uses an advanced algorithm that compensates for pressure and temperature
• Disposable desiccant cartridge assures accurate monitoring when loop has high humidity levels. (to be changed every 20-30 hours of diving – AP Diving recommend using the ‘Elapsed time’ feature to monitor protector duration) and protectors to be stored in their sealed packaging until ready for use)
• Can be used with or without existing APD Temp-Stik Scrubber monitor
• New mixing chamber supplied for mounting the CO₂ sensor
• Sensor is checked for operation during Vision Electronics start up
• Factory calibrated during assembly and simply zeroed during oxygen sensor calibration
• Low power consumption and powered by the Vision rebreather batteries
• Suitable for use with all diving gas mixes

The AP Diving CO₂ Sensor utilises infrared absorption technology to determine the CO₂ content of the breathing loop. The characteristics of infrared wavelength are dependent on the gas the light travels through. Therefore by measuring this wavelength the partial pressure of CO₂
in the gas can be determined with great accuracy.

One issue that had to be overcome was the potential for water-vapour to distort the readings, as water has a very similar effect on infrared wavelength as carbon dioxide. This was solved by developing a very effective sensor protector - a replaceable drying cartridge that consists of a desiccant sandwiched between protective technical membranes. 

Utilising the QinetiQ patented sensor and AP’s algorithms which compensate for depth and gas densities combined with AP’s manufacturing knowhow has resulted in the production of an accurate, water and water vapour proof product.

The AP CO₂ sensor represents a huge jump in underwater CO₂ measurement.

(includes 3 x sensor protectors)