React Pro Computer - Algorithm question

I have a total of four of the older React Pros (Before 2009) for my family and one of the newer models (mfg 2010- with the white background around the face) as a spare.

Recently I was diving with both an older model and the newer one. During the dive, the newer model said that I had 10 minutes NDL and indicated two diamonds in the caution area of the nitrogen bar graph. The older computer indicated 24 minutes NDL with no diamonds in caution. The new computer is console-mounted on my HP hose and the older computer was in my bc pocket so both should indicate the same.

Why the difference? What is the reason for this discrepancy? Which one should I trust?

Even before the new model was introduced the Genesis was considered in magazine reviews to be a "conservative" computer. Are the newer ones even MORE conservative? If so, why? If I go by the data on the new one it will seriously cut in to my BT.

Should I consider going to another brand for consistency?

Something is not right here as both computers have the same computation of NDL's. Please contact an authorized dealer and maybe bring in both computers or print out the log of the dives. Is is possible one of the computers (maybe new one) was in gauge mode? The dealer should be able to verify the mode, operation, etc and some stores have a "pressure pot" where they could simulate a dive to show the differences. It seems more to do with settings than brand as far as the varied NDL's you are getting.
Safe diving,
Team Sherwood

if you got 24 minutes, then you got 24 minutes.

Hi Mr. Sherwood Rep,

I read you response to my post. I appreciate your input. I do have a couple of comments....

According to the new-model owner's manual,page 42, if/when diving in Gauge Mode, there are no decompression or o2 monitoring functions displayed. The manual states that the display shows only Bottom Time, Depth and Ascent Rate.

When I became aware of the NDL discrepancy between the 2 computers (Discovered during a dive), both computers were most definitely indicating the Nitrogen Bar Graph, and NDL time.

In my mind, the only thing that could cause two computers (running the same algorithm) to have two completely different results would be if one were configured for nitrox. I checked this, too, and both were configured for Air.

Also to note. The new computer is console mounted on the hp hose; it is not allowed to flop around; it is attached so that is hangs a few inches from my belly. The older model computer was in my bc pocket... only inches away from the console-mounted computer.

My local dive shop does not have the pressure pot you described. I cannot do a download as apparently my download cable/software will only work with the older model.

Absent the ability to do a download, this is the data I can retrieive from a review from the computer lcd screen. Both computers were used on a sequence of 5 dives.

Computer #1, (Older model) serial # BG-007012; loG 7, 08-07-2011 10:39AM,
bt=:53; AIR; MAX FEET=50; Nitrogen Bar Graph = Last indicator before "Caution Zone; Log 1:01
--
Computer #2, (NEW model) serial # CT-000592 LoG 6, 08-07-2011 10:41AM,
bt=:53; AIR; MAX FEET=53; Nitrogen Bar Graph = TWO indicators IN "Caution Zone; Log 1:01
--------------


Computer #1, (Older model) serial # BG-007012; Log 6, 08-07-2011 8:45AM
bt=:51; AIR; MAX FEET=68; Nitrogen Bar Graph = ONE indicator in "Caution Zone; Log 16:24
--
Computer #2, (NEW model) serial # CT-000592 LoG 5, 08-07-2011 8:46AM,
bt=:51; AIR; MAX FEET=71; Nitrogen Bar Graph = THREE indicators in "Caution Zone; Log 16:24

(note: The first and third NiBG markers of the caution area are on, the second one is not on. This condition is on this log entry only; it displays normally on all other entries.)
--------------


Computer #1, (Older model) serial # BG-007012; Log 5, 08-06-2011 3:19PM
bt= 1:01; AIR; MAX FEET=59; Nitrogen Bar Graph = THREE indicators in "Caution Zone; Log :53
--
Computer #2, (NEW model) serial # CT-000592 Log 4, 08-06-2011 3:21PM
bt= 1:01; AIR; MAX FEET=61; Nitrogen Bar Graph = THREE indicators in "Caution Zone; Log :53
---------------


Computer #1, (Older model) serial # BG-007012; Log 4, 08-06-2011 1:27PM
bt= :58; AIR; MAX FEET=60; Nitrogen Bar Graph = Next to Last indicator before "Caution Zone]; Log 22:06
--
Computer #2, (NEW model) serial # CT-000592 Log 3, 08-06-2011 1:29PM
bt= :58; AIR; MAX FEET=62; Nitrogen Bar Graph = ONE indicators in "Caution Zone; Log 22:06


So, what do you think? I see that one registers 2-3 feet deeper than the other one. This I suppose could have a tiny effect, but not the differences I have seen..

Thanks

Any chance the 3 feet difference is a freshwater/saltwater setting?

Where were you diving,ocean or inland with a bit of altitude?

Hi ianr33

All the dives shown were salt walter- Gulf of Mexico.
The computers do not have a setting for salt or fresh.

Good thought, though. I just don't believe a difference of 2 or 3 ft would produce the differences in no-decompression time remaining that I was seeing.

One of the computers is simply wrong somehow.
The old one, if it's wrong, could be putting me in danger of excessive nitrogen.
The new one, if it's wrong, is short-changing me on bottom time. I'm not good with that, either.

I guess, on my next trip, I have to get my wife's and 2 daughters' computers and dive with them all. That way I'll have a sack full of them to compare!

Thanks for the input.

maybe you should download the data onto a computer? One computer might have been consistently a few feet deeper than the other, hence higher nitrogen level, even though they might have the same max depth.

Please contact an authorized dealer with your proof of purchase for the computers in question. If they are not able to test it, they will contact us direct and we will test it and inspect it. We will need to physically have the computers to test dive them. If you can find a dealer with a pressure pot, it may save time but if not, we will take a look at any computer in warranty.
Safe diving,
Team Genesis