Oxygen meter unit

[Styx]

We have just got liquid nitrogen plummed into our lab for temp tests.
We are after an atmousphere oxygen metre (realtime) that would sound an audiable alarm if the oxygen concentration dropped below a set percentage (say 15%)

Early warning if we have a leak/loose connection.


RS/Farnell sell hand-held personal sensors but no wall-mount mains power unit,

any ideas?

 

[stevez]

Sorry I can recall the manufacturer's name but we did exactly as you describe in an area where we had lots of people using machines with nitrogen piped to them. This was in the mid-80s so I'd think you can find what you need. Look to recognized safety standards to determine the proper levels of alarm - don't guess at the right levels. I use Armstrong Monitoring Corp stuff out of Canada for CO and NOx (exhaust fumes) but don't know if they make Oxygen sensors.

You might try contacting your gas supplier. Linde, among others, may be able to point you in the right direction.

 

[williB]

would am automotive O2 sensor work for you.?

 

[Styx]

As long as it can be wall mounted, have an audiable alarm, oxgen concentration standards (good point stevez) and pref mains powered then anything would do

 

[jbeng]

The units I have the most experience with are the Drager Polytron 2 units. They will detect a whole range of gasses, depending on which sensor you have installed. They're wall-mount, but not mains powered, but a 24VDC power supply would be all you would need to power it.
Here's a link for a company that represents Drager: **broken link removed**

Other gas monitoring equipment is made by MSA and Gastech (and a whole bunch of other companies).

JB

 

[mechie]

Oxygen depleted atmospheres

Try **broken link removed**

If this is intended to be commercial/industrial/schools (anything non-private) then you will have LEGAL responsibilities to maintain a healthy atmosphere in this lab. This will involve having periodic traceable calibrations of the oxygen detector so you may need to buy some test gasses or consult some local cal facility for them to test on your behalf (keep records!).

Should you have emergency respirator sets to allow rescues should the worst happen? and training to use this equipment?

Maybe the HSE could give you some guidance ?
**broken link removed**

 

[lavenatti]

Mechie is right about making sure of the calibration.

The oxygen meters I have used were so notorious for drift we used to calibrate them with a can of calibration gases or 100% O2 before each use.

Another safety feature may be to have the alarm open a solenoid valve on an oxygen bottle. This could ensure a breathable atmosphere and the noise of rushing gas could wake you out of an oxygen deprived stupor.