Analox Oxygen Sensor

[TheHuth]

I just got a used Analox O2EII handheld unit. It came to me with a low battery, so I swapped that out. But at the moment it only reads between .1 and .3 depending on how far I twist the calibration knob. I suspect it also has a bad sensor. But I dont want to throw money at it if its a dead unit. Does what I described above sound like what you would expect with a bad sensor? Or would it register much higher even if it was bad?

 

[dm9876]

Hi,

Are you certain that .1 and .3 don't represent 10% and 30%? If not then it sounds dead.

Normal practice would be to test it against Air and calibrate to 20.9 but then also a known reference gas. Maybe you have some 32% around

Some great articles (probably way more than you ever wanted to know) here:

Dive Gear Express® | Official Site | Dive Gear Express®
A relevant quote from the last paragraph of that one "Typical life of an analyzer sensor is somewhere between 24 and 48 months (I've seen plenty of them last 60 months and longer)"

Understanding Oxygen Sensors • ADVANCED DIVER MAGAZINE • byPaul Raymaekers

useful info from this article on checking the manufacture date of the sensor, keeping in mind that it could legitimately be on the shelf (in the packet) for up to a year after that.

"The production date of sensors is printed on the sensors, in different ways. Two common methods are:
- 3 numbers where the first indicates the last number of the production year, and the 2 others the month (example: 805XXX : 5th month of 2008, or may 2008)
- a letter followed by a number, where the letter indicates the month, and the number the last number of the year (example: A8 : January 2008)"

So based on that, if your manufacture date of the cell is more than 5 or 6 years ago, there is probably zero chance that the cell has any life left.

If you have a multi-meter then you can also check the cell (without the analyser box). they should read about 10mV in Air.

Dean

 

[TheHuth]

Its definitely reading .1 through .3 depending on how far out I set the calibration knob. I'm 90% sure its just a dead cell. But again I dont want to throw good money at a bad device. I dont think I have a multimeter (pretty sure I loaned it out and never got it back). But maybe you can help me decipher the numbers on the sensor.

Part Number is 9220-9B
Serial Number is 735269

Is it maybe a born on of the 35th week of 2007? If thats the case, its almost 9 years old.

 

[dm9876]

not sure... this thread seems to suggest a different format that does not match those numbers

Analox O2EII Sensors ; Understanding the Date Code

 

[gopbroek]

If you need a new sensor DGX has an aftermarket cell for $75. I have used them in the past without issues.

 

[Stoo]

I won't pretend to be an expert, but there really isn't much to these things other than the sensor I don't think. Sensors die a normal death even when not being used. But the more it's used, the faster it dies. If you have the inlet cap, use it.

I suspect if you replace the sensor, you'll be good to go. If not, but a new analyser and you'll have a spare sensor. (Keep it in a plastic bag, in the fridge.)

 

[TheHuth]

If you need a new sensor DGX has an aftermarket cell for $75. I have used them in the past without issues.

Is it the PSR-11-39-MD? It looks pretty much the same as the Analox one. I did see this as well: Vandagraph 0110224 R-33DE Oxygen Sensor Oxygen Sensors

I was considering that one, but wasnt looking forward to waiting for it to ship to the states. If the DGX one fits, I'll probably buy one of those.

I won't pretend to be an expert, but there really isn't much to these things other than the sensor I don't think. Sensors die a normal death even when not being used. But the more it's used, the faster it dies. If you have the inlet cap, use it.

I suspect if you replace the sensor, you'll be good to go. If not, but a new analyser and you'll have a spare sensor. (Keep it in a plastic bag, in the fridge.)

I tend to think you're right. I read the manual and in the troubleshooting section it did mention if your sensor reads zero, its probably bad. Then I noticed the range for the device is .1 to 100.0. So that tells me .1 is as low as it can read; aka zero.

 

[gopbroek]

I used the PSR-11-37-52D, here is a link to their page:
Specialty Oxygen Sensors (Analyzers) | Dive Gear Express®

 

[TheHuth]

Thanks, I'll order one of those today.

 

[TheHuth]

Thanks to all who replied. I bought the sensor from Dive Gear Express. Looks like this unit is back in business.