Shearwater unable to read 3rd oxygen sensor

paintedfrogfish · 5th June 2008, 14:15

Hi all
I live in Singapore and recently while passing through the USA someone fitted a Shearwater on a cable to my Meg head via the 'A' port. After using it for a few days the Shearwater could only get zero millivolts on the 3rd sensor (but it was OK on the APECS primary and secondary), so I couldn't use the Shearwater to continuously monitor my PO2, although I could always use it in dive computer mode. Does anyone have any instructions on how to check the connection of the cable to the oxygen sensor? Thanks.

Marcus

silentscuba · 5th June 2008, 23:57

Quote: (Originally Posted by paintedfrogfish)

Hi all
I live in Singapore and recently while passing through the USA someone fitted a Shearwater on a cable to my Meg head via the 'A' port. After using it for a few days the Shearwater could only get zero millivolts on the 3rd sensor (but it was OK on the APECS primary and secondary), so I couldn't use the Shearwater to continuously monitor my PO2, although I could always use it in dive computer mode. Does anyone have any instructions on how to check the connection of the cable to the oxygen sensor? Thanks.

Marcus

You need to clean all the connections on the bad cell and recalibrate in O2, and you might find that it starts working again. It sounds like that cell was voted out and maybe had a temporary fault in the circuit.

To further trouble shoot you will need a volt/ohm meter and check the pins on the Fischer connector.

Looking at the end of the Fischer connector on the end of your cable with the red dot on the outside of the case pointing at 12:00 the first pin right under the dot is Cell #1, the next pin to the right and down is Cell #2 and the next one down is Cell #3 with the center pin being the common.

Check to see if you have voltage between the pin in question and the center pin.

You need to verify if you have a cable, connection or computer problem.

I hope this helps.

paintedfrogfish · 6th June 2008, 15:41

Thanks, appreciate the advice. I was also told that I may have a loose connection to the Molex on the 3rd cell. I'll check it out this weekend.
Marcus

5th June 2008, 14:15	#1 (permalink)
paintedfrogfish New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2007 Location: Singapore Posts: 11	Shearwater unable to read 3rd oxygen sensor Hi all I live in Singapore and recently while passing through the USA someone fitted a Shearwater on a cable to my Meg head via the 'A' port. After using it for a few days the Shearwater could only get zero millivolts on the 3rd sensor (but it was OK on the APECS primary and secondary), so I couldn't use the Shearwater to continuously monitor my PO2, although I could always use it in dive computer mode. Does anyone have any instructions on how to check the connection of the cable to the oxygen sensor? Thanks. Marcus __________________ http://marcuslim.onexposure.net
(Offline)

5th June 2008, 23:57	#2 (permalink)
silentscuba rEvo CCR Driver Current Rebreather/s: Classic Kiss rEvo Other Rebreather/s: Inspiration Classic rEvo Join Date: Jun 2005 Location: Mill Creek, WA USA Posts: 586	Re: Shearwater unable to read 3rd oxygen sensor Quote: (Originally Posted by paintedfrogfish) Hi all I live in Singapore and recently while passing through the USA someone fitted a Shearwater on a cable to my Meg head via the 'A' port. After using it for a few days the Shearwater could only get zero millivolts on the 3rd sensor (but it was OK on the APECS primary and secondary), so I couldn't use the Shearwater to continuously monitor my PO2, although I could always use it in dive computer mode. Does anyone have any instructions on how to check the connection of the cable to the oxygen sensor? Thanks. Marcus You need to clean all the connections on the bad cell and recalibrate in O2, and you might find that it starts working again. It sounds like that cell was voted out and maybe had a temporary fault in the circuit. To further trouble shoot you will need a volt/ohm meter and check the pins on the Fischer connector. Looking at the end of the Fischer connector on the end of your cable with the red dot on the outside of the case pointing at 12:00 the first pin right under the dot is Cell #1, the next pin to the right and down is Cell #2 and the next one down is Cell #3 with the center pin being the common. Check to see if you have voltage between the pin in question and the center pin. You need to verify if you have a cable, connection or computer problem. I hope this helps. __________________ Curt McNamee rEvo CCR Diver KISS CCR Diver www.silentscuba.com
(Online)

6th June 2008, 15:41	#3 (permalink)
paintedfrogfish New Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2007 Location: Singapore Posts: 11	Re: Shearwater unable to read 3rd oxygen sensor Thanks, appreciate the advice. I was also told that I may have a loose connection to the Molex on the 3rd cell. I'll check it out this weekend. Marcus __________________ http://marcuslim.onexposure.net
(Offline)

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