Wisdom 2 altitude sensor

[airizzy]

I have a Wisdom 2 that seems to be having a problem with sensing altitude.

Background story.

Last month I was diving at an elevation of 5600ft. The computer altitude code read LEV3. This made perfect sense especially with the low pressure system in the area. After entering the water and starting a descent the code changed to LEV2 and the dive was logged in that setting. After the surface interval prior to the next dive the computer again read LEV3 and once again switched to LEV2 during the decent. I thought it was odd but didn't think much of it.

Several weeks later I was diving at 4750ft. I never looked at the computer setting at that point because it was a 12ft deep pool and didn't need a depth gauge. Afterward I looked at the logged dives and saw that all of them had been logged with SEA. I had never seen SEA on my computer before. This was very odd. The computer had always shown LEV2 or LEV3 depending on the barometric pressure.

Even though I live at 4700ft now my computer will not leave SEA and the NDL times in the plan mode corresponds to the 0-2000 ft limit on the DSAT table in the manual. I took it to the dive shop and I was told it was sent to Sherwood for evaluation. I was told that a tech called and said that the computer was fine and I needed to read page 95 of the manual. The story my dive shop owner told me seemed to have a lot of holes in it and I got a vibe that the computer was never sent to Sherwood at all. I could be wrong, but I asked to see the service report and she said that she had no additional information.

As it stands now, I have a computer that computes sea level NDL times even though I am almost 5000ft. I don't trust it and that makes it worthless in my mind. So what is the next step. Is there something I don't understand? Do I need to send it back to Sherwood for further evaluation? Please help me understand.

 

[SDAnderson]

Diagnosing a problem like this over the internet is a waste of time. Contact Sherwood or your dealer.

 

[airizzy]

Already did. Maybe the post wasn't clear. The dealer said they sent it in to Sherwood and that it checked out. But it is still reading SEA and showing a sea level NDL time even though I am at 4700ft. Also there was no service documentation. All the info she gave me is what she said was told her over the phone. She said that the tech said to read page 95 of the manual and that I didn't have the settings correct. Any tech from Sherwood would know that there are no settings for the altitude adjustment, it's automatic. I would like to hear back from the Sherwood rep to get his take.

 

[Sherwood SCUBA rep.]

We just contacted Airizzy direct by phone and we are getting the computer back here for further testing. We confirmed the computer did in fact come back and it was processed so quick, Airizzy did not think it had come back. We apologize for not including a detail of our testing procedure. Once the computer issue is resolved, we hope Airizzy witll post postive results. Thank you Airizzy for bringing this to our attentions.
Safe diving,
Team Sherwood

 

[airizzy]

I was a little surprised to have the senior sales rep for Sherwood Scuba on my phone the day after I posted my original complaint. This to me is proof positive that Sherwood is serious about resolving customer problems. The computer is on its way back to Sherwood. Apparently it is difficult to test the altitude function of the computer in the lab at sea level. When the tech searched the logbook he saw that altitude dives had been made and concluded that it was working and sent it back as a good computer. Per Sherwood's request I took pictures of the alt reading and plan mode at different altitudes. Here is a part of the letter I sent with the computer.

"At this point the computer registers SEA at 4700ft. When it was new it would read EL02 or EL03 depending on the current sea level barometric pressure. At Tom’s request I took the computer for a drive up the hill. At 5100ft the computer remained at SEA with a NDL of 4:20 at a depth of 30ft in the plan mode. At 5600ft the computer did change to EL02 and showed a NDL of 3:21 at 30ft. At 6500ft the computer still showed EL02 with a NDL of 3:21. I spent at least 20 min at each location to ensure a new reading would be taken. It appears that where the computer should be switching to EL02 at 3000 ft it is switching somewhere over 5000ft. I am sending pictures taken at different altitudes. I did not get pictures at 6500ft. For the tech, the sea level barometric pressure was 1012.2 milibars, slightly below standard pressure.

I don’t know why nor know of any reason how the computer could have been damaged to change its behavior since new. It is my experience that electrical equipment can and occasionally do thing that shouldn’t be possible. In this situation, if the computer is not reducing the NDL until over 5000ft and a dive was made at that altitude, it would be possible to over shoot the NDL time by almost 20 min on a 60ft dive. This is based on the DSAT NDL table in the manual. I have no idea what the computer would do on a repetitive dive but it could get a little scary."

I would like to thank Tom at Sherwood Scuba for calling and discussing this with me. I apologize for any trouble I may have made with my post on Scuba Board. At the time I wrote it I felt like the tech had told me I didn’t know what I was talking about. While that may still be the case I am grateful for the service. I am also grateful for the prompt service from Inland Scuba. For such a small shop they have great attitudes and have been very helpful with my scuba needs. My only suggestion would be to complete and send a detailed service/inspection report for items sent in. As we saw, it is easy to misunderstand telephone messages as they are relayed from person to person.

Thank you again.
Airizzy

 

[Charlie99]

I don’t know why nor know of any reason how the computer could have been damaged to change its behavior since new.

Your computer, like most others, almost certainly measures altitude with the same sensor that measures depths down to something like 300'.

So it has a full scale range around 150psi (approximate pressure at 300').

At 3000', the pressure is only about 1.5psi less than at the surface.

So it doesn't take much of an error in the pressure sensor to show up as a significant error in altitude.

It sounds like Sherwood needs to get a "negative pressure pot" with a slightly reduced pressure so they can easily test the altitude measurement of their computers.

 

[airizzy]

Sherwood decided to replace my computer. I picked up the new one yesterday and it works great. Thank you to Tom at Sherwood and your willingness to follow through with my problem. I never expected to hear from anyone at Sherwood except a quick post that I should send it back in. To have the sales rep on my phone the day after I posted my first complaint is nothing but impressive to me. I liked my Sherwood products before, but now I feel even better about all the money spent on Sherwood items. These items include: SR1 Reg, Blizzard Reg, Wisdom 2, Axis BCD, Tortuga BCD, Gemini Octo, Minimus Octo, and several gauge consoles. I haven't even mentions the Genesis items I have purchased. I will be proud to have Sherwood as my dive buddy any day.

Airizzy

 

[eshorvath]

I have a Wisdom 2 as well. I have done all my dives on it over the last year at sealevel. Recently I moved to a higher altitude, and have discovered my altitude sensor isnt working either. I sent this to a shop, kind of locally, for annual service and with hope they will fix the altitude issue as well. Hope it works out...

 

[vickivicki]

I have a Wisdom 2 as well. I have done all my dives on it over the last year at sealevel. Recently I moved to a higher altitude, and have discovered my altitude sensor isnt working either. I sent this to a shop, kind of locally, for annual service and with hope they will fix the altitude issue as well. Hope it works out...

 

[vickivicki]

DO NOT BUY THIS PRODUCT , THERE IS NO CUSTOMER SERVICE IF YOUR PRODUCT FAILS