Inspo Handsets – Diving Techniques

pchanning

In the interests of not hi-jacking another similar thread, I thought I’d start another:

Question: Is it necessary to inspect both handsets or just the one that is the Master?

I ask, as having one less dangly/ thing to look at floats my boat and in the context of failure I can always retrieve the Secondary (or new Master) for inspection.

I’m thinking that the alarm architecture would have incorporated this in its design ie: stray readings, much like it does for the cells.

I haven’t interrogated the literature so feel free to flame me for asking.

cheers

paul

Mark Chase

In answer to thaat I would point out that last week the batery packed up in the slave hand set?? Fortunatly on the boat but it could easily have been in the water.

ATB

Mark Chase

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Padowan

The problems with only considering one handset are as follows, whichever single handset you chose, there is a downside.

If you chose the Master handset all the time, and stow the slave somewhere, you are guaranteed that the unit is controlling PPO2 to the numbers displayed on the handset you are looking at. BUT if the slave handset has been inadvertantly switched off (or not switched on at all) you will not be notified of a problem, and could effective be running without a fallback. You may look down and see the master handset dead, and then find the slave handset dead, perhaps closely followed by you being dead too.

If you look at the slave handset primarily, you will always know that the fallback system is operational, but you cannot guarantee that the handset you are looking at is displaying the tru PPO2 that the loop is controlling to, as during it's slave mode it's purely passive.

Personally, I check the master handset, at intervals regular enough that if I do find it dead, and then on checking the slave is dead too, the loop PPO2 should still be life sustaining...

I have both handsets clipped onto the inner coulterlung D-Rings, the slave (left) clipped first to the right C-Lung ring, then the master (right) clipped to the left ring. It's done in this order so that the master handset is effectifely on top, but both are accessible enough if I need to check more than the master. I find that they are very unobtrusive here, easy to reach and check and don't dangle about at all...

Si

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ROB DAVIE

Senor Greekavian,

Here is a possible scenario, Paul. See what you think. As you know, the Slave handset just sits there, once the unit is turned on and calibrated, reflecting the info from the Master. If the Master fails, the Slave picks up immediately at that point and continues controlling.

At some point, the battery on the Slave goes down. Since you don't see this, the Master goes merrily on its way, until it has a problem, for whatever reason. You reach for your Slave and taa-daa, "Usted conoce nada!". (Which in Spanish means you are out of luck, brother!)

Suddenly, unless you have a fourth cell plugged in (a highly recommended idea) you are flying blind and guessing at your PPO2.

I am sure you would agree this is a less than desirable situation.

For myself, I clip the handsets together and attach them to a retractor. That way I can reach one-handed, pull them both up, glance at them by scanning across both sets of readouts, and release them to tuck themselves against my body.

JMPPO2's worth.

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Decodiver

You must check both handsets for the above reasons.

I teach this at all CCR levels.

If you check a handset on the surface and it is switched off, do not check the backup, inject O2 immediately. Then check the backup and switch on the other one.

If you check a handset at depth and it is switched off, do not check the backup, inject Diluent immediately. Then check the backup and switch the other back on.

Cheers,

Dave Cooper.

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pchanning

Thank you all for the info.

With regard to the above, I suffered a spate of the slave being switched-off by using the above method but ONLY when I ran the handsets down the inside of the counterlungs. They were clipped together and held with a retractor.

The problem was one of my handset cables is longer than the other thus one sat below the other, so apon moving them up and down (for inspection) they rubbed past each other and the square edges made easy work of flipping the power switch. The problem is SERIOUS as there is no audio warning when powering down the slave. This happened to me three times in one dive..!! Never did it again. Now I keep them apart.

Just an observation. Thanx again and dive safe.

cheers

paul

ROB DAVIE

Paul,

Reference your post above, sounds like a good argument for some of those fine MR handset covers!

Rob

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PCDiver

I can't find those covers for the handsets on the Internet. How can they be ordered? How much are they? Anybody have a picture?

Thanks,

Peter

plazma

http://www.btinternet.com/~madmole/DiverMole/DMSupplies.htm#Handset%20Covers

-Pasi

Mdemon

I jumped in at the weekend after a monster pre-dive fettle. Did the life check - lo and behold, Slave off. Just goes to show, it can happen with no physical contact at all...

During the fettle I replaced both batteries, but only had enough zinc oxide tape to wrap around one battery. Guess which one "bounced" on entry and turned itself off...?

FWIW, mine are just clipped together in the middle and left dangling on the front pouch - pick up one, pick up both, so I get to check both even if just to check there are some numbers. There is a SS double-ender attached which I can clip to the inner CL D-ring to keep it out of the way, or to clip to the shotline or whatever. HTH.

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