Interesting results?

[redacted]

I have no doubt that selling mags is their number one priority it still seems strange though that they would give two of the top offerings from the same sponsor, I mean manufacturer, different results. Something seems off to me.

What do you think is more important, good science or good editing? I suspect their testing methods may be the underlying problem.

 

[buddhasummer]

I suspect you are correct.

 

[rhwestfall]

I have no doubt that selling mags is their number one priority it still seems strange though that they would give two of the top offerings from the same sponsor, I mean manufacturer, different results. Something seems off to me.

I like what you did there....

Personally, I love the new G260.. Well, I love the fact folks are dumping G250 & G250V stages to get the new ones. I've scored a bunch of them lately (along with a pair of MK-20's) for very little. Most were near pristine. I now have some travel gear.....

 

[scubafanatic]

I have no doubt that selling mags is their number one priority it still seems strange though that they would give two of the top offerings from the same sponsor, I mean manufacturer, different results. Something seems off to me.

Certainly bears re confirming the results to rule out typos, flawed procedures, etc.

 

[buddhasummer]

I've sent them an email, will post back when I receive a reply.

 

[skippy11v2]

Personally, I like the A700 over the G260, simply because I get more moisture from the A700. I would rather service a A700 as well since the air barrel is attached to the case, one less piece to remove. I can tune either to breath the same ( at least to me on the bench and water). I tend to move to metal second stages these days. I still love my D400 but find I grab my A700 or Abyss for the diving I currently do.

 

[kelemvor]

According to the scubalab page, this is how the tests were conducted:

HOW WE SCORE
ANSTI breathing simulator results shown here are based on a score of 1 to 5, where 5 represents excellent performance with work-of-breathing measurements of 1 joule per liter or less at carefully regulated depths and breathing rates and volumes.
HOW WE TEST
ScubaLab put these regs through two tests — the first is conducted on a breathing simulator (objective), and the second by our team of test divers (ergonomic).
OBJECTIVE TESTING

We conducted tests on an ANSTI wet breathing simulator at Dive Lab, a commercial test facility in Panama City Beach, Florida. The simulator measures the effort (work of breathing) required to move air through a regulator as it is subjected, under- water, to a precise series of depths and breathing rates.
The simulator pressurizes the test chamber to simulate depths of 132 fsw, 165 fsw and 198 fsw. Each “breath” by the machine moves 2.5 liters of air through the regulator, at breathing rates of 15, 25 and 30 breaths a minute. These precisely measured volumes of air — 2.5 liters multi- plied by the breathing rate — are called Respiratory Minute Volumes (RMVs).
37.5 RMV @ 132 fsw:
This represents the maximum recreational depth at a somewhat aggressive breathing rate.
75 RMV @ 132 fsw:
This simulates the potential demand at maximum recreational depth for a diver at an extremely heavy work rate, or loosely simulates two divers buddy breathing at a somewhat aggressive rate.
62.5 RMV @ 165 fsw:
This represents the European conformance standard EN250, and is also the depth and breathing rate commonly used by manufacturers when determining a regulator’s performance.
62.5 RMV @ 198 fsw:
This is the U.S. Navy’s Class A test depth and breathing rate (although the Navy uses a higher HP supply pressure than we do). The simulator monitors how much effort is required to breathe, measuring the work of breathing in joules per liter (j/l). In our ratings, a score of 1=3j/l or greater; 2 = 2.26-3.0 j/l; 3 = 1.51-2.25 j/l; 4 = 1.1-1.50 j/l; and 5=1j/l or less.
We don’t test on the simulator for a pass/fail grade, but to objectively gauge performance in carefully controlled conditions. You can see how each reg performed on the breathing simulator in the charts that accompany the reviews.
ERGONOMIC TESTING
We conducted these tests at Alexander Springs in Florida with a team of divers who recorded their scores during their dives using underwater slates and waterproof test sheets. Divers evaluated each regulator in 13 specific performance areas, assigning scores from 5 (excellent) to 1 (poor), and recording their observations and comments about factors that determine the comfort and performance of the reg while they were actually being used.
ERGO TEST CATEGORIES

1 Ease of breathing in swimming position
2 Ease of breathing in head-up position
3 Ease of breathing in head-down position
4 Wetness in normal swimming position
5 Wetness in head-down and odd positions
6 Bubble interference in normal swimming position
7 Bubble interference in vertical/stationary position
8 Ease of clearing regulator using the blowing method
9 Ease of clearing regulator using the purge button
10 Purge button stiffness and comfort
11 Comfort of mouthpiece
12 Venturi lever adjustment function and effectiveness
13 Breathing- adjustment-knob function and effectiveness
​

Seems like a reasonable attempt to compare equipment to me. The linked screenshots only include breathing simulator results and omit subjective "ergo" results.

I'm surprised the Posieden didn't do better, and disappointed that they tested such a limited variety of regulators. I've been eyeing Atomic and Posieden for some time now.

---------- Post added November 16th, 2015 at 11:10 PM ----------

Actually, I can't find the subjective score anywhere. Maybe they forgot to include it!

 

[skippy11v2]

According to the scubalab page, this is how the tests were conducted:


Seems like a reasonable attempt to compare equipment to me. The linked screenshots only include breathing simulator results and omit subjective "ergo" results.

I'm surprised the Posieden didn't do better, and disappointed that they tested such a limited variety of regulators. I've been eyeing Atomic and Posieden for some time now.

Personally when there are reviews with a panel of individuals doing the testing, personal bias will enter the results, I do not believe they scew the results but they do enter the results. Bench testing regulators in my opinion does not necessarily equate to a difference that an average diver will be able to tell a difference at 50 Fsw with. Equipment intensive sports/hobbies bring bias to the users, that has to be reflected in reviewers.

How many freshly certified divers have all their gear from the same manufacturer? Is that the best gear for them, probably not, but it is what the shop/online where they were comfortable to purchase had to offer. As divers mature and they acquire more equipment the broader the manufacturers represented in their Kit seems to be.

I think the lack of bias from the machine coupled with the bias of human nature tends to skew the results of these tests.

 

[buddhasummer]

I agree with what you say, but in this case it's just the machine results that are in question.

 

[skippy11v2]

I agree with what you say, but in this case it's just the machine results that are in question.

So the machine tests are :

The simulator pressurizes the test chamber to simulate depths of 132 fsw, 165 fsw and 198 fsw. Each “breath” by the machine moves 2.5 liters of air through the regulator, at breathing rates of 15, 25 and 30 breaths a minute. These precisely measured volumes of air — 2.5 liters multi- plied by the breathing rate — are called Respiratory Minute Volumes (RMVs).


If that is the limits the average recreational diver are diving then the results are relevant, I work in an area where anything outside of recreational limits are prohibited due to chamber access, so 165FSW is not really relevant.. If anyone thinks their reg breathe the same at 40 FSW as 198FSW then they may want to retake a theory class..