Compressor and smoke distance

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

A few years back we caught tanks with 30ppm CO in them with my tester. The compressors intake snorkel was up a tall palm tree about 30m away from the generator, but it sucked in enough CO to negate the hopcalite filter and putting enough CO in the tanks to kill us.
 
A few years back we caught tanks with 30ppm CO in them with my tester. The compressors intake snorkel was up a tall palm tree about 30m away from the generator, but it sucked in enough CO to negate the hopcalite filter and putting enough CO in the tanks to kill us.
I really doubt that much CO could come from that intake. It probably was produced by the overheated compressor itself burning its own lubricating oil.

Great that you have a CO tank tester and caught it tho. It gets boring checking tanks with zero after zero, until you get a hit...!!
 
Most divers I’ve come across don’t know you can purchase a handheld CO tester for $28-40 at Walmart, Lowe’s, or Home Depot. I’ve seen handheld CO testers specially for scuba diving selling for $395. I’m weird and always test my tank refills. I do it by using my reg to fill a gallon ziplock bag with my tester inside. It might be kinda diy janky but it works. In case your wondering you can hyper ventilate or blow smoke in the gallon ziplock bag and the $28 meter will register the CO ppm.
 
Most divers I’ve come across don’t know you can purchase a handheld CO tester for $28-40 at Walmart, Lowe’s, or Home Depot.
Yes, and every bedroom & hotel room should have one. Many homes don't and most hotel rooms don't, but they should. I take one with me on all overnight travels.

Worthless as a scuba tank tester, tho. They're not going to react to CO in the 5-15 ppm range. You'd hate it if it did, as that'd be a false alarm in a home. Check your specs.

In case your wondering you can hyper ventilate or blow smoke in the gallon ziplock bag and the $28 meter will register the CO ppm.
If you blow enough smoke into a bag to set one off, you must be smoking some harsh stuff - or maybe it's also reacting to the moisture in the bag.
 
Yes, and every bedroom & hotel room should have one. Many homes don't and most hotel rooms don't, but they should. I take one with me on all overnight travels.

Worthless as a scuba tank tester, tho. They're not going to react to CO in the 5-15 ppm range. You'd hate it if it did, as that'd be a false alarm in a home. Check your specs.


If you blow enough smoke into a bag to set one off, you must be smoking some harsh stuff - or maybe it's also reacting to the moisture in the bag.

Have been using a GXG-1987. Range is 1ppm-1000ppm with +/- 10ppm. It has a sample button and is not an alarm. The $399 Palm CO scuba device is +/- 5 ppm.
 
Have been using a GXG-1987. Range is 1ppm-1000ppm with +/- 10ppm. It has a sample button and is not an alarm.
Who makes that one? All I can find online is sales listings. It's one thing to post claims on a sale listing, but I can't find any detailed specs. One Amazon page with several reviews includes several negative comments, like this one...
This CO meter is very competitively priced but is inaccurate. Tested with a 35ppm calibrated CO source, the unit measured 19ppm. I could accept a 10% calibration error (roughly 30 to 40 ppm reading around 35 ppm), not what I measured here. The response time was also slow, taking about 30sec to obtain a stable reading. A much more expensive commercial CO monitor had a stable reading in 5 sec. I wish I could recommend this meter, as it is well built and well priced, but I cannot because of the calibration issue.
$69 is indeed a nice price, but it doesn't sound reliable.

The $399 Palm CO scuba device is +/- 5 ppm.
That one probably works well.
 
I'm sure Vitas is still patiently waiting to have a few conversations, hey Dandy

So just briefly


Coroner's investigative report

IDENTITY


First name at birth Tasha Anne
Birth name Johnson-Wallace
Birth date 1950-09-07
Sex Female

IDENTIFICATION OF THE DECEASED PERSON

Ms. Johnson-Wallace was visually identified at the scene of her death.

CIRCUMSTANCES OF DEATH

On September 10, 2017, early in the afternoon, Ms. Johnson-Wallace participates with others people with advanced scuba diving training at Sacacomi Lake. Following a descent of about 60 feet, performed without problem, the lift is done according to the taught techniques. At about 15 feet from the surface, the instructor asks Ms. Johnson-Wallace to perform a mask drain, but she refuses or, at least, does sign of his inability to proceed. The instructor or the person named, in the middle, the "Dive master", supports her and shows her how to do it. Everything is successful at this moment and the next step is to go back at the decompression stops.

All of a sudden, the instructor realizes that Mrs. Johnson-Wallace is breathing quickly. he then takes a physical contact, that is to say by grasping it by a strap and in the looking in the eyes to reassure her. This lasts about 15 seconds. He leaves eyes his binomial (term designated for diving partner or "body") for 5 seconds to check what the other two students who are part of the training dive are doing. he always keep a physical contact with her. Turning to see her again, he finds that it does not have its regulator in the mouth. Between these two sequences, it flows about 30 seconds no more. The instructor tries, in vain, to replace her regulator.

In view of this lack of success, he carried out an emergency recovery during which, Mrs Johnson-Wallace does not move in any way, has wide eyes, does not seem to have breathing.

Arrived at the surface, follow a series of maneuvers of resuscitation, in less than one minute from the moment the instructor becomes aware of a difficulty. He shouts "help" and requests that 911 be dialed; he starts the artificial respiration technique commonly called "mouth-to-mouth" after taking off his mask. She does not do not breathe.
He pulls her to the shore and the maneuvers continue while student in the group rushes to remove her wet suit
for clear the abdomen. Another student arrives immediately and begins the chest compressions.

Less than a minute later, the group leader brings a defibrillator and the device
to oxygen. The instructor administers oxygen in continuous flow and compressions
thoracic are still in progress. Seconds later, the instructor responsible
activates the defibrillator (DEA), but other cardiopulmonary resuscitation techniques are
continue until paramedics arrive at 1339. The DEA does not recommend any shock.

Transportation to the nearest hospital is rapid, around 13:41, during which time
paramedics are busy trying to resuscitate, until the arrival at 14 h 06.

The medical staff in place immediately takes Ms. Johnson-Wallace in charge and
applies all possible resuscitation techniques until 2:18 pm, the hour of the report of deceased.


EXTERNAL EXAMINATION, AUTOPSY AND TOXICOLOGICAL ANALYSIS


An autopsy was performed on September 12, 2017 at the Laboratory of Forensic Sciences and
forensic medicine in Montreal. In his report, the pathologist described, in his review of
lungs, a distinctly distended aspect of some cells that could be secondary to
rupture of alveolar walls during the ascent (distended and congested lungs, 940
grams each). He took into account the subcutaneous emphysema that would have been perceived at the neck
during resuscitation manoeuvres. In his comments, one can read that a drowning
remains plausible, but could have occurred after the victim lost her
regulator. This, he says, would not explain the origin of the incident and it would be more
of a consequence than of a cause. He also finds no traumatic lesions
significant and no evidence of intervention by a third party.
No other contributory injury to
death was observed.

Toxicological analyzes were performed at the Laboratory of Forensic Sciences and
forensic medicine in Montreal. The alcohol level was negative.
No other substance has been detected.



ANALYSIS


Ms. Johnson-Wallace was 67 years old. She was spending the weekend in a camp
development for divers. Her big wish was to get her diver card
advanced. Since his arrival until the day of the accident, all her colleagues
and instructors) described her as a dynamic person and that nothing left
believe she may not be fit to play this sport.

The day before, Saturday, September 9, 2017, she had made three deep-water dives and
the next day, a descent of nearly 75 feet.

The investigation was conducted by the Sûreté du Québec (MRC of Maskinongé) which, in its
report, notes that a problem occurred during the mask emptying exercise, that is, a
very common technique learned in scuba diving. Ms. Johnson-Wallace does not
run at the first instruction and we do not know why. Except that a recovery took place successfully.


The police were called around 1:00 pm, and took care of protecting the scene until
the arrival of an on-site investigator followed by a technician from the Forensic Identification Service (SIJ).

The people involved in this activity were met and reported that
Mrs. Johnson-Wallace's accompanying instructor spared no effort to
try to save her life. For example, they mentioned that the latter had made
breaths, chest compressions, and ensuring that the AED is brought as quickly as possible
possible.

The diving equipment belonging to the victim was kept in plain sight on the bank
Sacacomi Lake to be transported, under my prescription, for expert appraisals.


In addition, I consulted the dive incident report written by the instructor called the
"Dive master", in addition to the two statements made to the designated investigator. Following
comments made by the expert who examined all the equipment he claimed he did not see
Ms. Johnson-Wallace trying to put her emergency pressure regulator on
"Octopus" and that suddenly she became inert.

The equipment expertise also noted that Ms. Johnson-Wallace was able to
carry an additional 13 pounds of lead. But the investigation also showed that she had passed
a buoyancy test and it was determined that additional 13 pound lead shots
were required. We remember that she had done 3 other dives before with this
configuration of sinkers, no problem.

On the other hand, it appears from the observations
expertise that the regulator used by Ms. Johnson-Wallace was
not recommended under water at temperatures below 10 degrees Celsius (icing
is possible).
However, according to the dive profile and the "dive master" declaration, the water
could reach only 5 or 6 degrees Celsius at a depth of 60 feet.

Thus, the possibility of icing of the regulator has been examined during the present
investigation, because it is true that in the latter situation, the vast majority of the time, the Air flow remains open and becomes continuous at the expander. However, he arrives sometimes, but rarely, that there is obstruction of the regulator, especially in icy water (eg example, diving in the Arctic). Asked again at my request, the "dive master" has
mentioned that there was no continuous airflow from Ms.'s regulator
Johnson-Wallace, which minimizes the probability of occurrence of this hypothesis.


Moreover, by consulting experienced divers, I learned that a diver fully
conscious and alert who is facing an emergency with his main regulator will use
immediately his "Octopus" (2nd regulator), then try to solve the problem in a
second time.
In the case of Ms. Johnson-Wallace, I see that in very short
time, she became inanimate, had her eyes wide open and empty, while her
regulator was out of his mouth, floating in front of her. This table suggests discomfort
relatively sudden, in the context of a brief episode of faster breathing.

In short, the investigation suggests that Ms. Johnson-Wallace suffered a barotrauma
pulmonary,
with a possible resultant drowning.



CONCLUSION

Ms. Tasha Anne Johnson-Wallace is probably dead from drowning, but he is not

It is not possible at autopsy to determine the trigger.

This is an accidental death.

I, the undersigned, coroner, acknowledge that the date indicated, and the places, the causes, the circumstances described above were made to the best of my knowledge, as a result of my investigation, in faith of which I signed, in Saint-Lucien, this 17 July 2018.


Yvon Garneau, coroner




Hey mate, yeah you sho0ter_McGavin, hows about you and your relatives and friends in the medical field
immediately desist and find yourselves a different calling before you do a real idiotic stupidity somewhere

How about taking your pitchforks and chase down some vampires which I'm sure will bring equal success
 
Sounds like she probably panicked from the mask clearing exercise, possibly hyperventilated and fainted losing her regulator in the process and drowning. I don't see any notes about there being air left in the cylinder at all. Perhaps she emptied it? Some barotrauma from the ascent and/or attempted resuscitation isn't unheard of.

Maybe I misunderstood but it sounds like the actual physical examination of her body was done by a pathologist but the report was written by an attorney. And that there were no findings of foul play or causative (chemical) agent found. Based on the translation this makes sense even if its not a very satisfactory conclusion.
 
Who makes that one? All I can find online is sales listings. It's one thing to post claims on a sale listing, but I can't find any detailed specs. One Amazon page with several reviews includes several negative comments, like this one...

$69 is indeed a nice price, but it doesn't sound reliable.


That one probably works well.

I appreciate you bringing this to my attention. I’m starting to have my doubts on my meters accuracy now. Then again it probably better then nothing. I need to purchase a good O2 meter and was hoping to save a little during a Memorial Day sale. I need to talk with my local dive shop manager and see if we can do some experiments with my cheap handheld vs the expensive specific to scuba carbon monoxide meter. If my cheap meter is reading CO in higher ppm vs lower, I can live with that. Though if it’s the other way around.....well that’s not good at all. I honestly thought the scuba specific version was more money because of cost to build for a small market size.
 
Then again it probably better then nothing.
I don't think so. I think it's giving a false feeling of safety. When dealing in double digits of parts per million of a gas that has no taste or smell and can be produced internally by overheated compressors, accuracy really counts but can be severely challenged.

I need to talk with my local dive shop manager and see if we can do some experiments with my cheap handheld vs the expensive specific to scuba carbon monoxide meter.
You can ask, but it's not likely that they stock calibration CO. Besides, how many tests with how many variables would you need? If you want to do research, find out which sensor is used, then find official specs on that model, including rate of drift since that unit can't be calibrated I don't think. Then you'd have to also study how the unit actually displays in ranges with whatever the sensor reads.

If my cheap meter is reading CO in higher ppm vs lower, I can live with that. Though if it’s the other way around.....well that’s not good at all.
If one is inaccurate, it can go either way. The cheapest solution I have found with a reliable unit is the Sensorcon CO Inspector. I leave mine on all the time and carry it everywhere so it does multiple duties as a home & hotel room alarm, vehicle alarm, restaurant alarm, etc. - even on planes as they don't have alarms. For scuba, use a gallon ziplock. You can get some higher readings than accurate with the ambient air getting sucked in, but we're still working with "close enough." For example, Cozumel marina air will easily register double digits with all the boat motors, but a careful bag test done there should read below 10ppm, or do the test at sea - except I hate to wait. It's tough as advertised in their youtube videos, too. I ran mine thru the clothes washer with bleach attached to my khakis - no problem. Oh, the battery will last 2 years if on all of the time, and by then it's time to send it in for sensor & battery service.

Now sensor drift will happen. I am not going to mail mine in every six months for calibration service, so I allow for that. I do not remember how much drift is possible so I'll call their office again before the next trip. They've gone up a bit since I got mine, $159 now, but this guy is offering a new one for $115, free shipping. Sensorcon Portable Carbon Monoxide CO Detector/Meter/Monitor-Test Gas Appliances | eBay
 
https://www.shearwater.com/products/perdix-ai/

Back
Top Bottom