Air integration for tech dives

[Cio]

Because it doesn't gain anything? If you know your gas, knowing your gas twice doesn't gain anything. If you don't know your gas, you turn the dive. The second gauge means nothing.

It provides redundancy and since you turn your dive if you don't know your gas, seems like it could save a dive, no?

 

[PfcAJ]

It provides redundancy and since you turn your dive if you don't know your gas, seems like it could save a dive, no?

How? You either have the gas or you don’t.

 

[Tracy]

It provides redundancy and since you turn your dive if you don't know your gas, seems like it could save a dive, no?

How would it save a dive? If the gauges don't read the same, you don't know your gas and you turn your dive. If you have one that fails, you don't know your gas and you turn your dive.
If both fail, you don't know your gas and you turn the dive.

There is no safety advantage

 

[boriss]

How would it save a dive? If the gauges don't read the same, you don't know your gas and you turn your dive. If you have one that fails, you don't know your gas and you turn your dive.
If both fail, you don't know your gas and you turn the dive.

There is no safety advantage

If one fails you have a backup. For example a battery dies on the transmitter, you still have a backup SPG. No need to turn the dive is the point.

 

[Tracy]

If one fails you have a backup. For example a battery dies on the transmitter, you still have a backup SPG. No need to turn the dive is the point.

You don’t have a backup, you have conflicting information. Conflicting information means you don’t know your gas and you turn the dive.

 

[boriss]

You don’t have a backup, you have conflicting information. Conflicting information means you don’t know your gas and you turn the dive.

Something isn't coming through in that message... right now I have a transmitter and an SPG... I read the AI information on the Perdix screen. If the transmitter fails I'll fall back to the SPG. What conflicting information are you talking about? Why do you turn a dive? What am I missing here?

 

[Tracy]

Something isn't coming through in that message... right now I have a transmitter and an SPG... I read the AI information on the Perdix screen. If the transmitter fails I'll fall back to the SPG. What conflicting information are you talking about? Why do you turn a dive? What am I missing here?

Why do you assume the gauge is accurate if your transmitter isn't working? You have two sources of information telling you different things.
If your gauge reads empty and your transmitter says you have gas, do you continue the dive?
Conflicting information is no information.

 

[broncobowsher]

Tracy is right about that.

 

[tursiops]

Why do you assume the gauge is accurate if your transmitter isn't working?

Because you believe the gauge if that's all you have in the first place. So if the transmitter dies, now the SPG is all you have. What is the difference?

 

[Cio]

You don’t have a backup, you have conflicting information. Conflicting information means you don’t know your gas and you turn the dive.

With only 2 pressure reading sources prone to failure, you are correct, however, you really have 3 sources. giving you two verifiable systems.
Your AI, Your SPG and, consumption. Consumption is a definite (you will consume gas)

The general consensus for having a single pressure reading device is; Diver checks on surface, tank reads full, diver dives. If during the dive, the diver notices that the pressure isn't going down, diver knows there is an issue with the gauge or the manifold is shut. This works with one device prone to fail and one definite (gas is consumed during dive) for one verifiable system.

This is similar to SCR where one O2 sensor is fine since you have a device prone to fail and a definite FO2 to reference it to. (one verifiable system)

Adding AI with an SPG and having a failure, leaves you at any one of the configurations you recommend, The important part is that the definite is still available and to the attentive diver, it will be.

If AI fails you wont have conflicting readings, you wont have anything at all. If by some oddity the AI sticks, (I'm not sure this is possible) it will not reflect consumption, just like the gauge.
If the gauge fails, you will know because it is stuck and not reflecting consumption. A diver being able to catch this has been beaten to death and the diver should be able to do so.


Similar in SCR, if you add backup computer with a singe sensor in addition to the original, you now have 2 sensors, which for CCR rebreathers is a no no, but since you really have two independent systems that can be referenced to a definite, it can be done and adds redundancy that is usable. If one sensor fails, a flush can verify the good sensor and the computer with the bad sensor can be switched to OC bailout (fixed FO2) and the dive could continue with redundancy since two computers, one with O2 sensor and one with fixed FO2 is considered safe.

In essence AI and a SPG, referenced to assumed consumption give the diver two verifiable systems and the diver can dive with.